Willdan (WLDN) 10-K 17 Mar 21 2020 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Jan. 01, 2021	Mar. 15, 2021	Jul. 03, 2020
Document and Entity Information
Document Type	10-K
Document Annual Report	true
Document Transition Report	false
Document Period End Date	Jan. 1, 2021
Entity File Number	001-33076
Entity Registrant Name	WILLDAN GROUP, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	14-1951112
Entity Address, Address Line One	2401 East Katella Avenue
Entity Address, Address Line Two	Suite 300
Entity Address, City or Town	Anaheim
Entity Address, Postal Zip Code	92806
Entity Address, State or Province	CA
City Area Code	800
Local Phone Number	424-9144
Title of 12(b) Security	Common Stock, par value $0.01 per share
Trading Symbol	WLDN
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		12,237,257
Current Fiscal Year End Date	--01-01
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2020
Entity Central Index Key	0001370450
Amendment Flag	false
ICFR Auditor Attestation Flag	true
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Public Float			$ 276.4

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jan. 01, 2021	Dec. 27, 2019
Current assets:
Cash and cash equivalents	$ 28,405	$ 5,452
Accounts receivable, net of allowance for doubtful accounts of $2,127 and $1,147 at January 1, 2021 and December 27, 2019, respectively	60,403	57,504
Contract assets	62,426	101,418
Other receivables	6,405	4,845
Prepaid expenses and other current assets	5,564	6,254
Total current assets	163,203	175,473
Equipment and leasehold improvements, net	12,506	12,051
Goodwill	130,124	127,647
Right-of-use assets	20,130	22,297
Other intangible assets, net	64,256	76,837
Other assets	5,993	16,296
Deferred income taxes, net	14,111	9,312
Total assets	410,323	439,913
Current liabilities:
Accounts payable	41,372	34,000
Accrued liabilities	41,754	67,615
Contingent consideration payable	12,321	5,155
Contract liabilities	7,434	5,563
Notes payable	14,996	13,720
Finance lease obligations	248	375
Lease liability	5,844	5,550
Total current liabilities	123,969	131,978
Contingent consideration payable	2,999	4,891
Notes payable	98,178	116,631
Finance lease obligations, less current portion	236	191
Lease liability, less current portion	15,649	18,411
Other noncurrent liabilities	128	533
Total liabilities	241,159	272,635
Commitments and contingencies
Stockholders' equity:
Preferred stock, $0.01 par value, 10,000 shares authorized, no shares issued and outstanding
Common stock, $0.01 par value, 40,000 shares authorized; 12,160 and 11,497 shares issued and outstanding at January 1, 2021 and December 27, 2019, respectively	122	115
Additional paid-in capital	149,014	132,547
Accumulated other comprehensive loss	(488)	(396)
Retained earnings	20,516	35,012
Total stockholders' equity	169,164	167,278
Total liabilities and stockholders' equity	$ 410,323	$ 439,913

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Jan. 01, 2021	Dec. 27, 2019
CONSOLIDATED BALANCE SHEETS
Accounts receivable, allowance for doubtful accounts (in dollars)	$ 2,127	$ 1,147
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	40,000,000	40,000,000
Common stock, shares issued	12,160,000	11,497,000
Common stock, shares outstanding	12,160,000	11,497,000

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Jan. 01, 2021	Dec. 27, 2019	Dec. 28, 2018
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME
Contract revenue	$ 390,980	$ 443,099	$ 272,252
Direct costs of contract revenue (inclusive of directly related depreciation and amortization):
Salaries and wages	65,149	64,485	46,588
Subcontractor services and other direct costs	196,438	243,641	132,693
Total direct costs of contract revenue	261,587	308,126	179,281
General and administrative expenses:
Salaries and wages, payroll taxes and employee benefits	71,229	66,303	45,248
Facilities and facility related	10,481	8,568	5,600
Stock-based compensation	16,113	12,112	6,262
Depreciation and amortization	18,743	15,027	6,060
Other	29,054	23,600	17,030
Total general and administrative expenses	145,620	125,610	80,200
Income (loss) from operations	(16,227)	9,363	12,771
Other income (expense):
Interest expense, net	(5,068)	(4,900)	(700)
Other, net	1,626	193	90
Total other expense, net	(3,442)	(4,707)	(610)
Income (loss) before income taxes	(19,669)	4,656	12,161
Income tax expense (benefit)	(5,173)	(185)	2,131
Net income (loss)	(14,496)	4,841	10,030
Other comprehensive income (loss):
Net unrealized loss on derivative contracts	(92)	(396)
Comprehensive income (loss)	$ (14,588)	$ 4,445	$ 10,030
Earnings (loss) per share:
Basic	$ (1.23)	$ 0.43	$ 1.08
Diluted	$ (1.23)	$ 0.41	$ 1.03
Weighted-average shares outstanding:
Basic	11,793	11,162	9,264
Diluted	11,793	11,766	9,763

CONSOLIDATED STATEMENTS OF STOC

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Cumulative Effect, Period of Adoption, AdjustmentRetained EarningsRevision of Prior Period, Adjustment	Cumulative Effect, Period of Adoption, AdjustmentRevision of Prior Period, Adjustment	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Loss.	Retained Earnings	Total
Balances at Dec. 29, 2017			$ 88	$ 50,976		$ 19,588	$ 70,652
Balances (in shares) at Dec. 29, 2017			8,799,000
Increase (Decrease) in Stockholders' Equity
Shares of common stock issued in connection with employee stock purchase plan			$ 1	1,299			1,300
Shares of common stock issued in connection with employee stock purchase plan (in shares)			65,000
Shares of common stock issued in connection with incentive stock plan			$ 1	667			668
Shares of common stock issued in connection with incentive stock plan (in shares)			85,000
Unregistered sales of equity securities and use of proceeds (in shares)			(15,000)
Shares used to pay taxes on stock grants				(442)			(442)
Issuance of restricted stock award and units (in shares)			22,000
Stock issued to acquire business			$ 20	55,246			55,266
Stock issued to acquire business (in shares)			2,012,000
Stock-based compensation expense				6,262			6,262
Net income (loss)						10,030	10,030
Balances at Dec. 28, 2018			$ 110	114,008		30,171	144,289
Balances (in shares) at Dec. 28, 2018			10,968,000
Increase (Decrease) in Stockholders' Equity
Retained Earnings (Accumulated Deficit) | ASC 606	$ 553	$ 553
Shares of common stock issued in connection with employee stock purchase plan			$ 1	1,739			1,740
Shares of common stock issued in connection with employee stock purchase plan (in shares)			62,000
Shares of common stock issued in connection with incentive stock plan			$ 1	930			931
Shares of common stock issued in connection with incentive stock plan (in shares)			115,000
Shares used to pay taxes on stock grants			$ (2)	(2,878)			(2,880)
Shares used to pay taxes on stock grants (in shares)			(76,000)
Issuance of restricted stock award and units			$ 2	(2)
Issuance of restricted stock award and units (in shares)			213,000
Unregistered sales of stock			$ 1	1,699			1,700
Unregistered sales of stock (in shares)			53,000
Stock issued to acquire business			$ 2	4,939			4,941
Stock issued to acquire business (in shares)			162,000
Stock-based compensation expense				12,112			12,112
Net income (loss)						4,841	4,841
Net unrealized loss on derivative contracts					$ (396)		(396)
Balances at Dec. 27, 2019			$ 115	132,547	(396)	35,012	$ 167,278
Balances (in shares) at Dec. 27, 2019			11,497,000				11,497,000
Increase (Decrease) in Stockholders' Equity
Retained Earnings (Accumulated Deficit)							$ 35,012
Shares of common stock issued in connection with employee stock purchase plan			$ 1	2,223			2,224
Shares of common stock issued in connection with employee stock purchase plan (in shares)			94,000
Shares of common stock issued in connection with incentive stock plan			$ 1	1,081			1,082
Shares of common stock issued in connection with incentive stock plan (in shares)			119,000
Shares used to pay taxes on stock grants			$ (1)	(2,945)			(2,946)
Shares used to pay taxes on stock grants (in shares)			(95,000)
Issuance of restricted stock award and units			$ 6	(5)			1
Issuance of restricted stock award and units (in shares)			545,000
Stock-based compensation expense				16,113			16,113
Net income (loss)						(14,496)	(14,496)
Net unrealized loss on derivative contracts					(92)		(92)
Balances at Jan. 01, 2021			$ 122	$ 149,014	$ (488)	$ 20,516	$ 169,164
Balances (in shares) at Jan. 01, 2021			12,160,000				12,160,000
Increase (Decrease) in Stockholders' Equity
Retained Earnings (Accumulated Deficit)							$ 20,516

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Jan. 01, 2021	Dec. 27, 2019	Dec. 28, 2018
Cash flows from operating activities:
Net income (loss)	$ (14,496)	$ 4,841	$ 10,030
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	18,743	15,472	6,211
Deferred income taxes, net	(5,209)	(209)	(2,890)
(Gain) loss on sale/disposal of equipment	(15)	(8)	(12)
Provision for doubtful accounts	1,330	1,051	470
Stock-based compensation	16,113	12,112	6,262
Accretion and fair value adjustments of contingent consideration	7,707	(302)	(1,426)
Changes in operating assets and liabilities, net of effects from business acquisitions:
Accounts receivable	(4,229)	11,627	3,177
Contract assets	35,498	(34,598)	(11,539)
Other receivables	(1,192)	(2,714)	4,081
Prepaid expenses and other current assets	577	(343)	(154)
Other assets	9,955	(6,520)	(778)
Accounts payable	7,372	(6,294)	(1,583)
Accrued liabilities	(27,210)	16,761	(1,945)
Contract liabilities	1,871	315	(2,272)
Right-of-use assets	210	430	(64)
Net cash provided by operating activities	47,025	11,621	7,568
Cash flows from investing activities:
Purchase of equipment and leasehold improvements	(5,076)	(6,637)	(2,105)
Proceeds from sale of equipment	17	45	59
Cash paid for acquisitions, net of cash acquired		(71,756)	(124,344)
Net cash used in investing activities	(5,059)	(78,348)	(126,390)
Cash flows from financing activities:
Payments on contingent consideration	(1,433)	(1,381)	(4,296)
Payments on notes payable	(205)	(1,842)	(477)
Payments on debt issuance costs	(327)	(709)	(1,300)
Proceeds from notes payable	1,140		1,805
Borrowings under term loan facility and line of credit	24,000	138,000	70,000
Repayments under term loan facility and line of credit	(42,000)	(78,000)	(2,500)
Principal payments on finance leases	(549)	(639)	(367)
Proceeds from stock option exercise	1,082	931	668
Proceeds from sales of common stock under employee stock purchase plan	2,224	1,740	1,300
Proceeds from equity raise			55,266
Shares used to pay taxes on stock grants	(2,946)	(2,880)	(442)
Restricted Stock Award and Units	1
Proceeds from unregistered sales of equity		1,700
Net cash provided by (used in) financing activities	(19,013)	56,920	119,657
Net increase (decrease) in cash and cash equivalents	22,953	(9,807)	835
Cash and cash equivalents at beginning of period	5,452	15,259	14,424
Cash and cash equivalents at end of period	28,405	5,452	15,259
Cash paid during the period for:
Interest	5,031	4,169	494
Income taxes	174	4,052	3,163
Supplemental disclosures of noncash investing and financing activities:
Loss on cash flow hedge valuations, net of tax	(92)	(396)
Contingent consideration related to business acquisitions			943
Other working capital adjustment	1,179		63
Equipment acquired under finance leases	$ 467	$ 661	$ 462

ORGANIZATION AND OPERATIONS OF

ORGANIZATION AND OPERATIONS OF THE COMPANY	12 Months Ended
	Jan. 01, 2021
ORGANIZATION AND OPERATIONS OF THE COMPANY
ORGANIZATION AND OPERATIONS OF THE COMPANY	1. ORGANIZATION AND OPERATIONS OF THE COMPAN Y Willdan Group, Inc. (“Willdan”) is a provider of professional, technical and consulting services to utilities, private industry, and public agencies at all levels of government. As resources and infrastructures undergo continuous change, the Company helps organizations and their communities evolve and thrive by providing a wide range of technical services for energy solutions and government infrastructure. Through engineering, program management, policy advisory, and software and data management, the Company designs and delivers trusted, comprehensive, innovative, and proven solutions to improve efficiency, resiliency, and sustainability in energy and infrastructure. Basis of Presentation The Company has prepared its Consolidated Financial Statements in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”). The consolidated statement of stockholders' equity includes repurchases of shares of our common stock from employees to satisfy tax withholding obligations incurred in connection with the vesting of restricted stock or performance stock units, which amount is presented as a reduction of additional paid-in capital and common stock. Fiscal Years The Company operates and reports its annual financial results based on 52 or 53-week periods ending on the Friday closest to December 31. The Company operates and reports its quarterly financial results based on the 13-week period ending on the Friday closest to June 30, September 30, and December 31 and the 13 or 14-week period ending on the Friday closest to March 31, as applicable. Fiscal year 2020, which ended on January 1, 2021, was comprised of 53 weeks, with the first quarter consisting of 14 weeks and the remaining quarters consisting of 13 weeks each. Fiscal year 2019, which ended on December 27, 2019, and fiscal year 2018, which ended on December 28, 2018, was comprised of 52 weeks, with all quarters presented consisting of 13 weeks. All references to years in the notes to consolidated financial statements represent fiscal years. Principles of Consolidation The consolidated financial statements include the accounts of Willdan Group, Inc. and its wholly-owned subsidiaries and their respective subsidiaries. All significant intercompany balances and transactions have been eliminated in consolidation. Reclassifications Certain prior year amounts have been reclassified in the condensed consolidated balance sheets to conform to the current year presentation. Use of Estimates The preparation of consolidated financial statements in conformity with generally accepted accounting principles in the U.S. requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements. Estimates also affect the reported amounts of revenue and expenses during the reporting period. Actual results could differ from those estimates. Cash and Cash Equivalents All highly liquid investments purchased with a remaining maturity of three months or less are considered to be cash equivalents. The Company from time to time may be exposed to credit risk with its bank deposits in excess of the FDIC insurance limits and with uninsured money market investments. The Company has not experienced any losses in such accounts and believes it is not exposed to any significant credit risk on cash and cash equivalents. Fair Value of Financial Instruments The Company uses the three-tier hierarchy of fair value measurement, which prioritizes the inputs. These tiers include: Level 1 (the highest priority), defined as observable inputs, such as quoted prices in active markets, Level 2, defined as inputs other than quoted prices in active markets that are either directly or indirectly observable; and Level 3 (the lowest priority), defined as unobservable inputs in which little or no market data exists, therefore requiring an entity to develop its own assumptions. ​ The Company’s financial instruments consist primarily of cash, cash equivalents, accounts receivable, contract assets, other receivables, prepaid expenses and other current assets, accounts payable, accrued liabilities and contract liabilities. The carrying amounts of certain other assets and contingent consideration are discounted to their present value because the time between the origination of these instruments and their expected realization or payment is greater than one year. ​ As of January 1, 2021 and December 27, 2019, the carrying amounts of the Company's cash and cash equivalents, accounts receivable, contract assets, other receivables, prepaid expenses and other current assets, accounts payable, accrued liabilities and contract liabilities, approximate their fair values because of the relatively short period of time between the origination of these instruments and their expected realization or payment. The carrying amounts of debt obligations approximate their fair values since the terms are comparable to terms currently offered by local lending institutions for loans of similar terms to companies with comparable credit risk. ​ The carrying amounts of the derivative financial instrument is valued based on Level 2 inputs. ​ Variable Interest Entities The Company accounts for variable interest entities in accordance with Accounting Standards Codification (“ASC”) 810, Consolidation. Under ASC 810, a variable interest entity (“VIE”) is created when any of the following criteria are present: (a) the equity investment at risk in the entity is not sufficient to permit the entity to finance its activities without additional subordinated financial support provided by other parties, including the equity holders; (b) the entity’s equity holders as a group either (i) lack the direct or indirect ability to make decisions about the entity, (ii) are not obligated to absorb expected losses of the entity or (iii) do not have the right to receive expected residual returns of the entity; or (c) the entity’s equity holders have voting rights that are not proportionate to their economic interests, and the activities of the entity involve or are conducted on behalf of the equity holder with disproportionately few voting rights. If an entity is deemed to be a VIE pursuant to ASC 810, the enterprise that has both (i) the power to direct the activities of a VIE that most significantly impact the entity’s economic performance and (ii) the obligation to absorb the expected losses of the entity or right to receive benefits from the entity that could be potentially significant to the VIE is considered the primary beneficiary and must consolidate the VIE. In accordance with ASC 810, the Company performs ongoing reassessments of whether an enterprise is the primary beneficiary of a VIE. As of January 1, 2021, the Company had one VIE — Genesys Engineering, P.C. (“Genesys”). Pursuant to New York law, the Company does not own capital stock of Genesys and does not have control over the professional decision making of Genesys’s engineering services. The Company, however, has entered into an administrative services agreement with Genesys pursuant to which WES, the Company’s wholly-owned subsidiary, will provide Genesys with ongoing administrative, operational and other non-professional support services. The Company manages Genesys and has the power to direct the activities that most significantly impact Genesys’s performance, in addition to being obligated to absorb expected losses from Genesys. Accordingly, the Company is the primary beneficiary of Genesys and consolidates Genesys as a VIE. Management also concluded there is no noncontrolling interest related to the consolidation of Genesys because management determined that (i) the shareholder of Genesys does not have more than a nominal amount of equity investment at risk, (ii) WES absorbs the expected losses of Genesys through its deferral of Genesys’s service fees owed to WES and the Company has, since entering into the administrative services agreement, had to continuously defer service fees for Genesys, and (iii) the Company believes Genesys will continue to have a shortfall on payment of its service fees for the foreseeable future, leaving no expected residual returns for the shareholder. For more information regarding Genesys, see Note 8 “Commitments and Variable Interest Entities.” Segment Information The Company presents segment information externally consistent with the manner in which the Company’s chief operating decision maker reviews information to assess performance and allocate resources. The Company’s two segments are (i) Energy, and (ii) Engineering and Consulting. Willdan Group, Inc. (“WGI”) is a holding company and performs administrative functions on behalf of its subsidiaries, such as treasury, legal, accounting, information systems, human resources and certain business development activities, and earns revenue that is only incidental to the activities of the enterprise. As a result, WGI does not meet the definition of an operating segment. Contract Assets and Liabilities Billing practices are governed by the contract terms of each project based upon costs incurred, achievement of milestones or pre-agreed schedules. Billings do not necessarily correlate with revenue recognized using the percentage-of-completion method of revenue recognition. Contract assets include unbilled amounts typically resulting from revenue under contracts where the percentage-of-completion method of revenue recognition is utilized and revenue recognized exceeds the amount billed to the customer. In addition, contract assets include retainage amounts withheld from billings to the Company’s clients pursuant to provisions in our contracts. Contract liabilities consist of advance payments and billings in excess of revenue recognized and deferred revenue. Adoption of ASC 606 On December 30, 2017, the Company adopted ASC 606, using the modified retrospective method applied to those contracts which were not completed as of December 29, 2017. Prior to adopting ASC 606, the Company established an implementation team, which included senior managers from its finance and accounting group. The implementation team evaluated the impact of adopting ASC 606 on its contracts expected to be uncompleted as of December 30, 2017 (the date of adoption). The evaluation included reviewing its accounting policies and practices to identify differences that would result from applying the requirements of the new standard. The Company identified and made changes to its processes, systems and controls to support recognition and disclosure under the new standard. The implementation team worked closely with various professional consultants and attended several formal conferences and seminars to conclude on certain interpretative issues. The Company recognizes engineering and consulting contract revenue over time using the percentage-of-completion method, based primarily on contract cost incurred to date compared to total estimated contract cost. Revenue on the vast majority of its contracts will continue to be recognized over time because of the continuous transfer of control to the customer. Revenue recognition for software licenses issued by the Energy segment is recognized at a point in time, upon acceptance of the software by the customer and in recognition of the fulfillment of the performance obligation. Certain additional performance obligations beyond the base software license may be separated from the gross license fee and recognized on a straight-line basis over time. ​ Contract Accounting The Company enters into contracts with its clients that contain various types of pricing provisions, including fixed price, time-and-materials, and unit-based provisions. The Company recognizes revenues in accordance with ASU 2014-09, Revenue from Contracts with Customer, codified as ASC Topic 606 and the related amendments (collectively “ASC 606”). As such, the Company identifies a contract with a customer, identifies the performance obligations in the contract, determines the transaction price, allocates the transaction price to each performance obligation in the contract and recognizes revenues when (or as) the Company satisfies a performance obligation. The following table reflects the Company’s two reportable segments and the types of contracts that each most commonly enters into for revenue generating activities. ​ Segment Contract Type Revenue Recognition Method ​ Time-and-materials Time-and-materials Energy Unit-based Unit-based ​ Software license Unit-based ​ Fixed price Percentage-of-completion ​ Time-and-materials Time-and-materials Engineering and Consulting Unit-based Unit-based ​ Fixed price Percentage-of-completion ​ Revenue on the vast majority of the Company’s contracts will continue to be recognized over time because of the continuous transfer of control to the customer. Revenue on fixed price contracts is recognized on the percentage-of-completion method based generally on the ratio of direct costs incurred-to-date to estimated total direct costs at completion. The Company uses the percentage-of-completion method to better match the level of work performed at a certain point in time in relation to the effort that will be required to complete a project. In addition, the percentage-of-completion method is a common method of revenue recognition in the Company’s industry. Many of the Company’s fixed price contracts involve a high degree of subcontracted fixed price effort and are relatively short in duration, thereby lowering the risks of not properly estimating the percent complete. Revenue on time-and-materials and unit-based contracts is recognized as the work is performed in accordance with the specific rates and terms of the contract. The Company recognizes revenues for time-and-materials contracts based upon the actual hours incurred during a reporting period at contractually agreed upon rates per hour and also includes in revenue all reimbursable costs incurred during a reporting period. Certain of the Company’s time-and-materials contracts are subject to maximum contract values and, accordingly, when revenue is expected to exceed the maximum contract value, these contracts are generally recognized under the percentage-of-completion method, consistent with fixed price contracts. For unit-based contracts, the Company recognizes the contract price of units of a basic production product as revenue when the production product is delivered during a period. Revenue recognition for software licenses issued by the Energy segment is generally recognized at a point in time, utilizing the unit-based revenue recognition method, upon acceptance of the software by the customer and in recognition of the fulfillment of the performance obligation. Certain additional performance obligations beyond the base software license may be separated from the gross license fee and recognized on a straight-line basis over time. Revenue for amounts that have been billed but not earned is deferred, and such deferred revenue is referred to as contract liabilities in the accompanying condensed consolidated balance sheets. To determine the proper revenue recognition method for contracts, the Company evaluates whether two or more contracts should be combined and accounted for as one single contract and whether the combined contract should be accounted for as one performance obligation. With respect to the Company’s contracts, it is rare that multiple contracts should be combined into a single performance obligation. This evaluation requires significant judgment and the decision to combine a group of contracts or separate a single contract into multiple performance obligations could change the amount of revenue and profit recorded in a given period. Contracts are considered to have a single performance obligation if the promise to transfer the individual goods or services is not separately identifiable from other promises in the contracts, which is mainly because the Company provides a significant service of integrating a complex set of tasks and components into a single project or capability. The Company may enter into contracts that include separate phases or elements. If each phase or element is negotiated separately based on the technical resources required and/or the supply and demand for the services being provided, the Company evaluates if the contracts should be segmented. If certain criteria are met, the contracts would be segmented which could result in revenues being assigned to the different elements or phases with different rates of profitability based on the relative value of each element or phase to the estimated total contract revenue. Segmented contracts may comprise up to approximately 2.0% to 3.0% of the Company’s consolidated contract revenue. Contracts that cover multiple phases or elements of the project or service lifecycle (development, construction and maintenance and support) may be considered to have multiple performance obligations even when they are part of a single contract. For contracts with multiple performance obligations, the Company allocates the transaction price to each performance obligation using the best estimate of the standalone selling price of each distinct good or service in the contract. For the periods presented, the value of the separate performance obligations under contracts with multiple performance obligations (generally measurement and verification tasks under certain energy performance contracts) were not material. In cases where the Company does not provide the distinct good or service on a standalone basis, the primary method used to estimate standalone selling price is the expected cost plus a margin approach, under which the Company forecasts the Company’s expected costs of satisfying a performance obligation and then adds an appropriate margin for the distinct good or service. The Company provides quality of workmanship warranties to customers that are included in the sale and are not priced or sold separately or do not provide customers with a service in addition to assurance of compliance with agreed-upon specifications and industry standards. The Company does not consider these types of warranties to be separate performance obligations. In some cases, the Company has a master service or blanket agreement with a customer under which each task order releases the Company to perform specific portions of the overall scope in the service contract. Each task order is typically accounted for as a separate contract because the task order establishes the enforceable rights and obligations, and payment terms. Under ASC 606, variable consideration should be considered when determining the transaction price and estimates should be made for the variable consideration component of the transaction price, as well as assessing whether an estimate of variable consideration is constrained. For certain of the Company’s contracts, variable consideration can arise from modifications to the scope of services resulting from unapproved change orders or customer claims. Variable consideration is included in the transaction price to the extent it is probable that a significant reversal of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is resolved. The Company estimates of variable consideration and determination of whether to include estimated amounts in the transaction price are based largely on assessments of legal enforceability, the Company’s performance, and all information (historical, current and forecasted) that is reasonably available to the Company. Due to the nature of the work required to be performed on many of the Company’s performance obligations, the estimation of total revenue and cost at completion is complex, subject to many variables and requires significant judgment. As a significant change in one or more of these estimates could affect the profitability of the Company’s contracts, the Company reviews and updates the Company’s contract-related estimates regularly through a company-wide disciplined project review process in which management reviews the progress and execution of the Company’s performance obligations and the estimate at completion (EAC). As part of this process, management reviews information including, but not limited to, any outstanding key contract matters, progress towards completion and the related program schedule and the related changes in estimates of revenues and costs. Management must make assumptions and estimates regarding labor productivity and availability, the complexity of the work to be performed, the cost and availability of materials, the performance of subcontractors, and the availability and timing of funding from the customer, among other variables. The Company recognizes adjustments in estimated profit on contracts under the cumulative catch-up method. Under this method, the impact of the adjustment on profit recorded to date is recognized in the period the adjustment is identified. Revenue and profit in future periods of contract performance is recognized using the adjusted estimate. If at any time the estimate of contract profitability indicates an anticipated loss on the contract, the Company recognizes the full amount of estimated loss in the period it is identified. Contracts are often modified to account for changes in contract specifications and requirements. The Company considers contract modifications to exist when the modification either creates new rights or obligations or changes the existing enforceable rights or obligations. Most of the Company’s contract modifications are for goods or services that are not distinct from existing contracts due to the significant integration provided in the context of the contract and are accounted for as if they were part of the original contract. The effect of a contract modification that is not distinct from the existing contract on the transaction price and the Company’s measure of progress for the performance obligation to which it relates is recognized as an adjustment to revenue (either as an increase in or a reduction of revenue) on a cumulative catch-up basis. For contract modifications that result in the promise to deliver goods or services that are distinct from the existing contract and the increase in price of the contract is for the same amount as the standalone selling price of the additional goods or services included in the modification, the Company accounts for such contract modifications as a separate contract. The Company includes claims to vendors, subcontractors and others as a receivable and a reduction in recognized costs when enforceability of the claim is established by the contract and the amounts are reasonably estimable and probable of being recovered. The amounts are recorded up to the extent of the lesser of the amounts management expects to recover or to costs incurred. Billing practices are governed by the contract terms of each project based upon costs incurred, achievement of milestones or pre-agreed schedules. Billings do not necessarily correlate with revenue recognized using the percentage-of-completion method of revenue recognition. Direct costs of contract revenue consist primarily of that portion of technical and nontechnical salaries and wages that has been incurred in connection with revenue producing projects. Direct costs of contract revenue also include production expenses, subcontractor services and other expenses that are incurred in connection with revenue producing projects. Direct costs of contract revenue exclude that portion of technical and nontechnical salaries and wages related to marketing efforts, vacations, holidays and other time not spent directly generating revenue under existing contracts. Such costs are included in general and administrative expenses. Additionally, payroll taxes, bonuses and employee benefit costs for all Company personnel are included in general and administrative expenses in the accompanying consolidated statements of comprehensive income since no allocation of these costs is made to direct costs of contract revenue. No allocation of facilities costs is made to direct costs of contract revenue. Other companies may classify as direct costs of contract revenue some of the costs that the Company classifies as general and administrative costs. The Company expenses direct costs of contract revenue when incurred. Included in revenue and costs are all reimbursable costs for which the Company has the risk or on which the fee was based at the time of bid or negotiation. No revenue or cost is recorded for costs in which the Company acts solely in the capacity of an agent and has no risks associated with such costs. Accounts receivable are carried at original invoice amount less an estimate made for doubtful accounts based upon a review of all outstanding amounts on a quarterly basis. Management determines allowances for doubtful accounts through specific identification of amounts considered to be uncollectible and potential write-offs, plus a non-specific allowance for other amounts for which some potential loss has been determined to be probable based on current and past experience. The Company’s historical credit losses have been minimal with governmental entities and large public utilities, but disputes may arise related to these receivable amounts. Accounts receivable are written off when deemed uncollectible. Recoveries of accounts receivable previously written off are recorded when received. Retainage, included in contract assets, represents amounts withheld from billings to the Company’s clients pursuant to provisions in the contracts and may not be paid to the Company until specific tasks are completed or the project is completed and, in some instances, for even longer periods. At January 1, 2021 and December 27, 2019, contract assets included retainage of approximately $6.2 million and $5.4 million, respectively. In addition to the above, the Company derives revenue from software licenses and professional services and maintenance fees. In accordance with ASC 606, the Company performs an assessment of each contract to identify the performance obligations, determine the overall transaction price for the contract, allocate the transaction price to the performance obligations, and recognize the revenue when the performance obligations are satisfied. The Company utilizes the residual approach by which it estimates the standalone selling price by reference to the total transaction price less the sum of the observable standalone selling prices of other goods or services promised in the contract. The software license revenue is typically recognized at a point in time when control is transferred to the client, which is defined as the point in time when the client can use and benefit from the license. The software license is delivered before related services are provided and is functional without services, updates, or technical support. Related professional services include training and support services in which the standalone selling price is determined based on an input measure of hours incurred to total estimated hours and is recognized over time, usually which is the life of the contract. General and Administrative Expenses General and administrative expenses include the costs of the marketing and support staff, other marketing expenses, management and administrative personnel costs, payroll taxes, bonuses and employee benefits for all of the Company’s employees and the portion of salaries and wages not allocated to direct costs of contract revenue for those employees who provide the Company’s services. General and administrative expenses also include facility costs, depreciation and amortization, professional services, legal and accounting fees and administrative operating costs. Within general and administrative expenses, “Other” includes expenses such as provision for billed or unbilled receivables, professional services, legal and accounting, computer costs, travel and entertainment, marketing costs and acquisition costs. The Company expenses general and administrative costs when incurred. Leases In February 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2016-02, Leases (Topic 842) (“ASU 2016-02”). ASU 2016-02 require, among other things, that lessees recognize the following for all leases (unless a policy election is made by class of underlying asset to exclude short-term leases) at the commencement date: (1) a lease liability, which is a lessee’s obligation to make lease payments arising from a lease, measured on a discounted basis; and (2) a right-of-use asset, which is an asset that represents the lessee’s right to use, or the direct use of, a specified asset for the lease term. The FASB issued ASU 2018-11 on July 30, 2018, which allows entities to apply the provisions of ASC 842 at the effective date without adjusting comparative periods. ​ On December 29, 2018, the Company adopted ASU 2016-02 using the modified retrospective method. Under this guidance, the net present value of future lease payments is recorded as right-of-use assets and lease liabilities. In addition, the Company elected the ‘package of practical expedients’ permitted under the transition guidance within the new standard, which among other things, allowed the Company to carry forward the historical lease classification. In addition, the Company elected not to utilize the hindsight practical expedient to determine the lease term for existing leases. The Company also elected the practical expedient to not separate lease and non-lease components for its facilities leases. Previously, all of the Company’s office leases were classified as operating leases and rent expense was included in facilities expense in the consolidated statements of comprehensive income. ​ In addition, the Company leases certain equipment under financing leases. The economic substance of the leases is a financing transaction for acquisition of equipment and leasehold improvements. Accordingly, the right-of-use assets for these leases are included in the balance sheets in equipment and leasehold improvements, net of accumulated depreciation, with a corresponding amount recorded in current portion of financing lease obligations or noncurrent portion of financing lease obligations, as appropriate. The financing lease assets are amortized over the life of the lease or, if shorter, the life of the leased asset, on a straight-line basis and included in depreciation expense in the statements of comprehensive income. The interest associated with financing lease obligations is included in interest expense in the statements of comprehensive income. For more information, see Note 2, “ Recent Accounting Pronouncements Leases ​ Equipment and Leasehold Improvements Equipment and leasehold improvements are stated at cost less accumulated depreciation and amortization. Equipment under capital leases is stated at the present value of the minimum lease payments as of the acquisition date. Depreciation and amortization on equipment are calculated using the straight-line method over estimated useful lives of two Following are the estimated useful lives used to calculate depreciation and amortization: ​ ​ ​ ​ ​ Category Estimated Useful Life Furniture and fixtures 5 years Computer hardware 3 years Computer software 3 years Automobiles and trucks 3 years Field equipment 5 years ​ Goodwill Goodwill represents the excess of costs over fair value of the assets acquired. The Company completes its annual testing of goodwill as of the last day of the first month of its fourth fiscal quarter each year to determine whether there is impairment. Goodwill, which has an indefinite useful life, is not amortized, but instead tested for impairment at least annually or more frequently if events and circumstances indicate that the asset might be impaired. Impairment losses for reporting units are recognized to the extent that a reporting unit’s carrying amount exceeds its fair value. Long-lived assets Long-lived assets, such as equipment, leasehold improvements and purchased intangible assets subject to amortization are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to estimated undiscounted future cash flows expected to be generated by the

RECENT ACCOUNTING PRONOUNCEMENT

RECENT ACCOUNTING PRONOUNCEMENTS	12 Months Ended
	Jan. 01, 2021
RECENT ACCOUNTING PRONOUNCEMENTS
RECENT ACCOUNTING PRONOUNCEMENTS	2. RECENT ACCOUNTING PRONOUNCEMENTS Accounting Pronouncements Recently Adopted In June 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2016-13, “Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”). ASU 2016-13 requires entities to report “expected” credit losses on financial instruments and other commitments to extend credit rather than the current “incurred loss” model. These expected credit losses for financial assets held at the reporting date are to be based on historical experience, current conditions, and reasonable and supportable forecasts. ASU 2016-13 will also require enhanced disclosures relating to significant estimates and judgments used in estimating credit losses, as well as the credit quality. The Company adopted this standard effective December 28, 2019. The adoption of this standard did not have a material impact on the Company’s Condensed Consolidated Financial Statements. Accounting Pronouncements Recently Issued In March 2020, the FASB issued ASU No. 2020-04, “Reference Rate Reform (Topic 848): facilitation of the Effects of Reference Rate Reform on Financial Reporting” (“ASU 2020-04”). ASU 2020-04 provides optional expedients and exceptions for applying U.S. GAAP to contract modifications and hedging relationships that reference LIBOR or another reference rate expected to be discontinued because of reference rate reform. ASU 2020-04 provides, among other things, guidance that modifications of contracts within the scope of Topic 470, Debt, should be accounted for by prospectively adjusting the effective interest rate; modifications of contracts within the scope of Topic 840, Leases, should be accounted for as a continuation of the existing contract; and, changes in the critical terms of hedging relationships, caused by reference rate reform, should not result in the de-designation of the instrument, provided certain criteria are met. In January 2021, the FASB issued ASU No. 2021-01, “Reference Rate Reform (Topic 848) - Scope” (“ASU 2021-01”). ASU 2021-01 clarifies the scope and application of ASU 2020-04 and permits entities, among other things, to elect certain optional expedients and exceptions when accounting for derivative contracts and certain hedging relationships affected by changes in the interest rates used for discounting cash flows. The Company’s exposure to LIBOR rates includes its credit facilities and swap agreement. The amendments are effective as of March 12, 2020 through December 31, 2022. Adoption is permitted at any time. The Company is currently evaluating the impact this update will have on its Consolidated Financial Statements. In December 2019, the FASB issued ASU No. 2019-12, “Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes” (“ASU 2019-12”). ASU 2019-12 amends the accounting for income taxes by, among other things, removing: (i) The exception to the incremental approach for intraperiod tax allocation when there is a loss from continuing operations and income or a gain from other items (for example, discontinued operations or other comprehensive income); (ii) The exception to the requirement to recognize a deferred tax liability for equity method investments when a foreign subsidiary becomes an equity method investment; (iii) The exception to the ability not to recognize a deferred tax liability for a foreign subsidiary when a foreign equity method investment becomes a subsidiary; and (iv) The exception to the general methodology for calculating income taxes in an interim period when a year-to-date loss exceeds the anticipated loss for the year. The amendments are effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2020, which for the Company is the first quarter of fiscal 2021. The Company is currently evaluating the impact this update will have on its Consolidated Financial Statements. ​

SUPPLEMENTAL FINANCIAL STATEMEN

SUPPLEMENTAL FINANCIAL STATEMENT DATA	12 Months Ended
	Jan. 01, 2021
SUPPLEMENTAL FINANCIAL STATEMENT DATA
SUPPLEMENTAL FINANCIAL STATEMENT DATA	3. SUPPLEMENTAL FINANCIAL STATEMENT DATA Accounts Receivable Accounts receivable consisted of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ January 1, ​ December 27, ​ 2021 2019 ​ ​ (in thousands) Billed ​ $ 62,530 ​ $ 58,651 Unbilled (1) ​ ​ 56,262 ​ ​ 96,041 Contract retentions ​ ​ 6,164 ​ ​ 5,377 Other assets (2) ​ ​ 4,524 ​ ​ 14,075 ​ ​ ​ 129,480 ​ ​ 174,144 Allowance for doubtful accounts ​ ​ (2,127) ​ ​ (1,147) ​ ​ $ 127,353 ​ $ 172,997 ​ (1) Unbilled portion represents contract assets which is presented separately from accounts receivable on the consolidated balance sheets. (2) Other assets represents a portion of receivables greater than one year from the normal course of business presented separately from current assets on the consolidated balance sheets. ​ The movements in the allowance for doubtful accounts consisted of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fiscal Year ​ 2020 2019 2018 ​ ​ (in thousands) Balance as of the beginning of the year ​ $ 1,147 ​ $ 442 ​ $ 369 (Recovery of) provision for doubtful accounts ​ 1,329 ​ 1,051 ​ 470 Write-offs of uncollectible accounts ​ (388) ​ (346) ​ (397) Fair value adjustment ​ 39 ​ — ​ — Balance as of the end of the year ​ $ 2,127 ​ $ 1,147 ​ $ 442 ​ Billed accounts receivable represent amounts billed to clients that have yet to be collected. Unbilled accounts receivable represent revenue recognized, but not yet billed, pursuant to contract terms or accounts billed after the period end. Substantially all unbilled receivables as of January 1, 2021 and December 27, 2019 are, or were expected to be, billed and collected within twelve months of such date. Contract retentions represent amounts invoiced to clients where payments have been withheld pending the completion of certain milestones, other contractual conditions or upon the completion of the project. These retention agreements vary from project to project and could be outstanding for several months. Allowances for doubtful accounts have been determined through specific identification of amounts considered to be uncollectible and potential write-offs, plus a non-specific allowance for other amounts for which some potential loss has been determined to be probable based on current and past experience. Consolidated Edison of New York accounted for 31% of the Company’s outstanding receivables as of January 1, 2021. The Los Angeles Department of Water and Power (“LADWP”) accounted for 16% of the Company’s outstanding receivables as of December 27, 2019. From time to time, in connection with factoring agreements, the Company sells trade accounts receivable without recourse to third party purchasers in exchange for cash. During 2020 and 2019, the Company sold trade accounts receivable and received cash proceeds of $10.6 million and $4.9 million, respectively. The discounts on the trade accounts receivable sold during 2020 were $1.7 million and the discounts on the trade accounts receivable sold during 2019 were not material. Discounts on the trade accounts receivable were recorded within “Other, net” in other income (expense) in the consolidated financial statements. Equipment and Leasehold Improvements Equipment and leasehold improvements were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ January 1, ​ December 27, ​ ​ 2021 2019 ​ ​ (in thousands) Furniture and fixtures ​ $ 4,088 ​ $ 4,614 Computer hardware and software ​ 18,047 ​ 14,789 Leasehold improvements ​ 2,994 ​ 2,410 Equipment under finance leases ​ 2,370 ​ 1,957 Automobiles, trucks, and field equipment ​ 3,216 ​ 3,564 Subtotal ​ 30,715 ​ 27,334 Accumulated depreciation and amortization ​ (18,209) ​ (15,283) Equipment and leasehold improvements, net ​ $ 12,506 ​ $ 12,051 ​ Depreciation expense of equipment and leasehold improvements totaled $5.0 million, $3.4 million, and $1.6 million in fiscal years 2020, 2019, and 2018, respectively. Included in accumulated depreciation and amortization is $0.6 million, $0.5 million and $0.4 million of amortization expense related to equipment held under finance leases in fiscal years 2020, 2019, and 2018, respectively. Accrued Liabilities Accrued liabilities were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ January 1, ​ December 27, ​ 2021 2019 ​ ​ (in thousands) Accrued subcontractor costs ​ $ 19,124 ​ $ 45,366 Other ​ 11,981 ​ 4,630 Accrued bonuses ​ ​ 5,211 ​ ​ 7,756 Employee withholdings ​ 2,768 ​ 3,463 Compensation and payroll taxes ​ 1,983 ​ 3,286 Paid leave bank ​ 687 ​ 3,114 Total accrued liabilities ​ $ 41,754 ​ $ 67,615 ​ ​ ​

DERIVATIVE FINANCIAL INSTRUMENT

DERIVATIVE FINANCIAL INSTRUMENTS	12 Months Ended
	Jan. 01, 2021
DERIVATIVE FINANCIAL INSTRUMENTS
DERIVATIVE FINANCIAL INSTRUMENTS	4. DERIVATIVE FINANCIAL INSTRUMENTS The Company uses certain interest rate derivative contracts to hedge interest rate exposures on its variable rate debt. The Company’s hedging program is not designated for trading or speculative purposes. The Company recognizes derivative instruments as either assets or liabilities on the accompanying consolidated balance sheets at fair value. The Company records changes in the fair value (i.e., gains or losses) of the derivatives that have been designated as cash flow hedges in its consolidated balance sheets as accumulated other comprehensive income (loss) and in its condensed consolidated statements of comprehensive (loss) income as a loss or gain on cash flow hedge valuation. On January 31, 2019, the Company entered into an interest rate swap agreement that the Company designated as cash flow hedge to fix the variable interest rate on a portion of the Company’s 2018 Term Loan Facility. The interest rate swap agreement total notional amount of $35.0 million, has a fixed annual interest rate of 2.47% and expires on January 31, 2022. As of January 1, 2021, the effective portion of the Company’s interest rate swap agreement designated as a cash flow hedge before tax effects was $0.7 million, of which no amounts were reclassified from accumulated other comprehensive income to interest expense in fiscal 2020. The Company expects to reclassify $0.5 million from accumulated other comprehensive income to interest expense within the next twelve months. The fair values of the Company’s outstanding derivatives designated as hedging instruments were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value of Derivative ​ ​ Instruments as of ​ ​ Balance Sheet Location ​ January 1, 2021 ​ December 27, 2019 ​ ​ ​ ​ (in thousands) Interest rate swap agreement ​ Accrued liabilities ​ $ (624) ​ $ (241) Interest rate swap agreement ​ Other noncurrent (liabilities) assets ​ $ (48) ​ $ (306) ​ The impact of the effective portions of derivative instruments in cash flow hedging relationships and fair value relationships on other comprehensive income was $0.7 million for the year ended January 1, 2021. The accumulated balances and reporting period activities for the year ended January 1, 2021 related to reclassifications out of accumulated other comprehensive income (loss) are summarized as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gain (Loss) on ​ Accumulated Other ​ Derivative Instruments Comprehensive Loss ​ ​ (in thousands) Balances at December 28, 2018 ​ $ — ​ $ — Other comprehensive loss before reclassifications ​ ​ (546) ​ ​ (546) Amounts reclassified from accumulated other comprehensive income: ​ ​ ​ ​ ​ ​ Income tax benefit (expense) related to derivative instruments ​ ​ 150 ​ ​ 150 Net current-period other comprehensive loss ​ ​ (396) ​ ​ (396) Balances at December 27, 2019 ​ $ (396) ​ $ (396) Other comprehensive loss before reclassifications ​ ​ (126) ​ ​ (126) Amounts reclassified from accumulated other comprehensive income: ​ ​ ​ ​ ​ ​ Income tax benefit (expense) related to derivative instruments ​ ​ 34 ​ ​ 34 Net current-period other comprehensive loss ​ ​ (488) ​ ​ (488) Balances at January 1, 2021 ​ $ (488) ​ $ (488) ​

DEBT OBLIGATIONS

DEBT OBLIGATIONS	12 Months Ended
	Jan. 01, 2021
DEBT OBLIGATIONS
DEBT OBLIGATIONS	5. DEBT OBLIGATIONS Debt obligations, excluding obligations under finance leases (see Note 7, Leases, ​ ​ ​ ​ ​ ​ ​ ​ ​ January 1, December 27, ​ ​ 2021 ​ 2019 ​ ​ (in thousands) Outstanding borrowings on Term A Loan ​ $ 85,000 ​ $ 95,000 Outstanding borrowings on Revolving Credit Facility ​ ​ — ​ ​ 5,000 Outstanding borrowings on Delayed Draw Term Loan ​ ​ 27,000 ​ ​ 30,000 Other debt agreements ​ ​ 1,996 ​ ​ 1,060 Total debt ​ ​ 113,996 ​ ​ 131,060 Issuance costs and debt discounts ​ ​ (822) ​ ​ (709) Subtotal ​ ​ 113,174 ​ ​ 130,351 Less current portion of long-term debt ​ 14,996 ​ 13,720 Long-term debt portion ​ $ 98,178 ​ $ 116,631 ​ Credit Facilities On June 26, 2019, the Company and certain of its subsidiaries entered into an Amended and Restated Credit Agreement (as amended by the First Amendment, dated as of August 15, 2019, and the Second Amendment, dated as of November 6, 2019, the “Credit Agreement”) with a syndicate of financial institutions as lenders and BMO Harris Bank, N.A. (“BMO”), as administrative agent. The Credit Agreement provides for (i) a $100.0 million secured term loan (the “Term A Loan”), (ii) up to $50.0 million in delayed draw secured term loans (the “Delayed Draw Term Loan”), and (iii) a $50.0 million secured revolving credit facility (the “Revolving Credit Facility” and, collectively with the Term A Loan and the Delayed Draw Term Loan, the “Credit Facilities”), each maturing on June 26, 2024. The Company’s obligations under the Credit Agreement are guaranteed by its present and future domestic subsidiaries, with limited exceptions. Prior to the Third Amendment (as defined below), the Credit Agreement required the Company to comply with certain financial covenants, including requiring that the Company maintain a (i) total leverage ratio (the “Leverage Ratio”), defined as the ratio of total funded debt to Adjusted EBITDA (as defined in the Credit Agreement), of at least 3.50 to 1.00 through December 31, 2020, and 3.25 to 1.00 thereafter and (ii) fixed charge coverage ratio (“FCCR Ratio”), defined as the ratio of Adjusted EBITDA less Unfinanced Capital Expenditures (as defined in the Credit Agreement) to Fixed Charges (as defined in the Credit Agreement), of not less than The Credit Agreement also contains other customary restrictive covenants including (i) restrictions on the incurrence of additional indebtedness and additional liens on property, (ii) restrictions on permitted acquisitions and other investments and (iii) limitations on asset sales, mergers and acquisitions. Further, the Credit Agreement limits the Company’s payment of future dividends and distributions and share repurchases by the Company. Subject to certain exceptions, borrowings under the Credit Agreement are also subject to mandatory prepayment from (a) any issuances of debt or equity securities, (b) any sale or disposition of assets, (c) insurance and condemnation proceeds (d) representation and warranty insurance proceeds related to insurance policies issued in connection with acquisitions and (e) excess cash flow. The Credit Agreement includes customary events of default. Third Amendment to the Credit Agreement ​ On May 6, 2020, the Company entered into the Third Amendment to the Amended and Restated Credit Agreement (the “Third Amendment”) which, among other things, amends or suspends certain covenants contained in the Credit Agreement from March 5, 2020 until the earlier of (i) July 2, 2021 and (ii) the last day of the fiscal quarter in which the Company delivers an irrevocable election to terminate the covenant relief granted by the Third Amendment (the “Covenant Relief Period”). ​ The Third Amendment increases the maximum Leverage Ratio the Company is permitted to maintain during the Covenant Relief Period and replaces the covenant to maintain a minimum FCCR Ratio during the Covenant Relief Period with a requirement to maintain a minimum Adjusted EBITDA (as defined in the Third Amendment). ​ During the Covenant Relief Period, borrowings under the Credit Agreement bear interest (A) from March 5, 2020 until the date of the Third Amendment, at a rate equal to one-month LIBOR plus 2.0%, (B) from the date of the Third Amendment until the date the administrative agent received the Company’s financial statements for the quarter ended July 3, 2020, at a rate equal to one-month LIBOR, plus an applicable margin of 1.50% with respect to Base Rate borrowings and 2.50% with respect to LIBOR borrowings and (C) at all other times during the Covenant Relief Period, at a rate equal to either, at the Company’s option, (i) the highest of the prime rate, the Federal Funds Rate plus 0.5% or one-month LIBOR plus 1.00% or (ii) one-month LIBOR, in each case plus an applicable margin ranging from 0.125% to 1.50% with respect to Base Rate borrowings and 1.125% to 2.50% with respect to LIBOR borrowings, depending on the Leverage Ratio; provided, that one-month LIBOR shall not be less than 0.75% during the Covenant Relief Period. During the Covenant Relief Period, the Company will pay a commitment fee for the unused portion of the Revolving Credit Facility and the delayed draw term loan facility, which ranges from 0.15% to 0.45% per annum depending on the Leverage Ratio, and fees on the face amount of any letters of credit outstanding under the Revolving Credit Facility, which range from 0.84% to 2.50% per annum, in each case, depending on whether such letter of credit is a performance or financial letter of credit and the Leverage Ratio. ​ After the Covenant Relief Period, borrowings under the Credit Agreement will bear interest at a rate equal to either, at the Company’s option, (i) the Base Rate or (ii) one-month LIBOR, in each case plus an applicable margin ranging from 0.125% to 1.00% with respect to Base Rate borrowings and 1.125% to 2.00% with respect to LIBOR borrowings, depending on the Leverage Ratio; provided, that one-month LIBOR shall not be less than 0.00%. After the Covenant Relief Period, the Company will pay a commitment fee for the unused portion of the Revolving Credit Facility and the delayed draft term loan facility, which will range from 0.15% to 0.35% per annum depending on the Leverage Ratio, and fees on the face amount of any letters of credit outstanding under the Revolving Credit Facility, which will range from 0.84% to 2.00% per annum, in each case, depending on whether such letter of credit is a performance or financial letter of credit and the Leverage Ratio. ​ The Term A Loan issuance costs are amortized to interest expense over the term of the loan, and as of January 1, 2021, issuance costs of $0.8 million remained unamortized. The Delayed Draw Term Loan and Revolving Credit Facility issuance cost of $0.6 million are included in assets in the accompanying condensed consolidated balance sheets. The Term A Loan amortizes quarterly in installments of $2.5 million beginning with the fiscal quarter ending September 27, 2019, with a final payment of all then remaining principal and interest due on the maturity date of June 26, 2024. Each borrowing under the Delayed Draw Term Loan will amortize quarterly in an amount equal to 2.5% of the aggregate outstanding borrowings under the Delayed Draw Term Loan, beginning with the first full fiscal quarter ending after the initial borrowing date, with a final payment of all then remaining principal and interest due on the maturity date of June 26, 2024. The amounts outstanding under the Credit Facilities may be prepaid in whole or in part at any time without penalty. Willdan is the borrower under the Credit Agreement and its obligations under the Credit Agreement are guaranteed by its present and future domestic subsidiaries (other than any inactive subsidiaries and Factoring SPV (as defined in the Credit Agreement)). In addition, subject to certain exceptions, all such obligations are secured by substantially all of the assets of Willdan and the subsidiary guarantors. The Company believes that, as of January 1, 2021, it was in compliance with all covenants contained in the Credit Agreement, as amended by the Third Amendment. As of January 1, 2021, the Company’s composite interest rate, exclusive of the effects of upfront fees, undrawn fees and issuance cost amortization, was 2.8% and $2.7 million in letters of credit were issued. Other Debt Agreements Insurance Premiums The Company’s annual commercial insurance policy protection package renews in the fourth quarter of every year. From time to time, the Company will finance insurance premiums by entering into unsecured notes payable with insurance companies. During the Company’s annual insurance renewals in the fourth quarter of its fiscal year ended January 1, 2021, the Company elected to finance its insurance premiums for the 2021 fiscal year with a note payable bearing interest at an annual rate of 2.75%, payable in monthly principal and interest installments of $0.2 million through August 2021. As of January 1, 2021, the unpaid balance of the financed premiums totaled $1.1 million. During the Company’s annual insurance renewals in the fourth quarter of its year ended December 27, 2019, the Company did not finance any of its insurance premiums for the 2020 fiscal year. Software Agreements The Company has also financed, from time to time, software costs by entering into unsecured notes payable with software providers. During the fiscal year ended December 28, 2018, the Company elected to finance its IBM software costs of $0.2 million with a note payable bearing interest at an annual rate of 4.656%, payable in monthly principal and interest installments of $6,315 through November 2021. As of January 1, 2021, and December 27, 2019, the unpaid balance related to the IBM software agreement totaled $57,000 and $133,000, respectively. Utility Customer Agreement In connection with the acquisition of substantially all of the assets of Onsite Energy, the Company assumed a contract dispute settlement agreement between Onsite Energy and one of its utility customers dated December 20, 2018 (the “Utility Customer Agreement”) where Onsite Energy agreed to pay $1.7 million, bearing interest at an imputed annual rate of 4.332%, payable in quarterly principal and interest installments through June 2021. As of January 1, 2021 and December 27, 2019, the unpaid balance of the Utility Customer Agreement totaled $0.8 million and $0.9 million, respectively. Future Debt Payments The following table summarizes the combined principal installments for the Company’s debt obligations, excluding capital leases, over the next five years and beyond, as of January 1, 2021: ​ ​ ​ ​ Fiscal Year: ​ ​ ​ 2021 ​ 14,996 2022 ​ ​ 13,000 2023 ​ ​ 13,000 2024 ​ ​ 73,000 Total debt maturities ​ ​ 113,996 Issuance costs and debt discounts ​ ​ (822) Net carrying value ​ $ 113,174 ​

GOODWILL AND OTHER INTANGIBLE A

GOODWILL AND OTHER INTANGIBLE ASSETS	12 Months Ended
	Jan. 01, 2021
GOODWILL AND OTHER INTANGIBLE ASSETS
GOODWILL AND OTHER INTANGIBLE ASSETS	6. GOODWILL AND OTHER INTANGIBLE ASSETS As of January 1, 2021, the Company had $130.1 million of goodwill, which primarily relates to the Energy segment and the acquisitions within this segment of E3, Inc., Lime Energy, NAM, Integral Analytics and Abacus Resource Management Company (“Abacus”) and substantially all of the assets of Onsite Energy, The Weidt Group, Genesys and 360 Energy Engineers, LLC (“360 Energy”). The remaining goodwill relates to the Engineering and Consulting reporting segment and the acquisition within this segment of Economists LLC. The changes in the carrying value of goodwill by reporting unit were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 27, ​ Additional ​ Additions / ​ January 1, ​ 2019 Purchase Cost Adjustments 2021 ​ ​ (in thousands) Reporting Unit: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Energy ​ $ 126,898 ​ $ — ​ $ 2,477 ​ $ 129,375 Engineering and Consulting ​ ​ 749 ​ ​ — ​ ​ — ​ ​ 749 ​ ​ $ 127,647 ​ $ — ​ $ 2,477 ​ $ 130,124 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 28, ​ Additional ​ Additions / ​ December 27, ​ 2018 Purchase Cost Adjustments 2019 ​ ​ (in thousands) Reporting Unit: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Energy ​ $ 96,999 ​ $ 39,690 ​ $ (9,791) ​ $ 126,898 Engineering and Consulting ​ ​ 749 ​ ​ ​ ​ ​ ​ ​ ​ 749 ​ ​ $ 97,748 ​ $ 39,690 ​ $ (9,791) ​ $ 127,647 ​ impairment was recorded in any year during the three-year period ended January 1, 2021. The gross amounts and accumulated amortization of the Company’s acquired identifiable intangible assets with finite useful lives, included in other intangible assets, net in the accompanying consolidated balance sheets, were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ January 1, 2021 ​ December 27, 2019 ​ ​ ​ ​ ​ ​ ​ ​ Gross ​ Accumulated ​ Gross ​ Accumulated ​ Amortization ​ Amount Amortization Amount Amortization Period ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (in years) Finite: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Backlog ​ $ 7,944 ​ $ 6,249 ​ $ 7,134 ​ $ 3,763 ​ 1.0 Tradename ​ 15,911 ​ 6,984 ​ 13,351 ​ 4,882 2.5 ​ - ​ 6.0 Non-compete agreements ​ ​ 1,420 ​ ​ 1,390 ​ ​ 2,320 ​ ​ 1,384 ​ 4.0 ​ - ​ 5.0 Developed technology ​ ​ 15,500 ​ ​ 6,107 ​ ​ 14,620 ​ ​ 3,227 ​ 8.0 Customer relationships ​ 58,149 ​ ​ 14,248 ​ ​ 60,733 ​ ​ 8,065 5.0 ​ - ​ 8.0 Total finite intangible assets ​ $ 98,924 ​ $ 34,978 ​ $ 98,158 ​ $ 21,321 ​ ​ ​ ​ ​ ​ In-process research and technology (1) ​ ​ 310 ​ ​ — ​ ​ — ​ ​ — ​ ​ ​ ​ ​ ​ Total intangible assets ​ $ 99,234 ​ $ 34,978 ​ $ 98,158 ​ $ 21,321 ​ ​ ​ ​ ​ ​ ​ (1) In-process research and technology is not amortized until put into use. At the time of acquisition, the Company estimates the fair value of the acquired identifiable intangible assets based upon the facts and circumstances related to the particular intangible asset. Inherent in such estimates are judgments and estimates of future revenue, profitability, cash flows and appropriate discount rates for any present value calculations. The Company preliminarily estimates the value of the acquired identifiable intangible assets and then finalizes the estimated fair values during the purchase allocation period, which does not extend beyond 12 months from the date of acquisition. The Company’s amortization expense for acquired identifiable intangible assets with finite useful lives was $13.7 million, $11.6 million and $4.5 million for the fiscal years 2020, 2019 and 2018, respectively. Estimated amortization expense for acquired identifiable intangible assets for fiscal year 2021 and the succeeding years is as follows: ​ ​ ​ ​ ​ ​ ​ ​ Future Intangible Asset ​ ​ ​ Amortization expense ​ ​ ​ (in thousands) Fiscal year: ​ ​ ​ 2021 ​ ​ 11,543 2022 ​ 11,227 2023 ​ 9,928 2024 ​ ​ 6,806 2025 ​ ​ 6,235 Thereafter ​ ​ 18,517 ​ ​ $ 64,256 ​ ​

LEASES

LEASES	12 Months Ended
	Jan. 01, 2021
LEASES
LEASES	7. LEASES The Company leases certain office facilities under long-term, non-cancellable operating leases that expire at various dates through the year 2027. In addition, the Company is obligated under finance leases for certain furniture and office equipment that expire at various dates through the year 2023. On December 29, 2018, the Company adopted ASU No. 2016-02, Leases (Topic 842) using the modified retrospective method. Under this guidance, the net present value of future lease payments is recorded as right-of-use assets and lease liabilities. In addition, the Company elected the ‘package of practical expedients ’ permitted under the transition guidance within the new standard, which among other things, allowed the Company to carry forward the historical lease classification. In addition, the Company elected not to utilize the hindsight practical expedient to determine the lease term for existing leases. The Company elected the short-term lease recognition exemption for all leases that qualify. This means, for those leases that qualify, the Company did not recognize right-of-use assets or lease liabilities, including not recognizing right-of-use assets or lease liabilities for existing short-term leases of those assets in transition. The Company also elected the practical expedient to not separate lease and non-lease components for our facilities leases. From time to time, the Company enters into non-cancelable leases for some of our facility and equipment needs. These leases allow the Company to conserve cash by paying a monthly lease rental fee for the use of facilities and equipment rather than purchasing them. The Company’s leases have remaining terms ranging from one to eight years , some of which may include options to extend the leases for up to five years , and some of which may include options to terminate the leases within one year . Currently, all of the Company’s leases contain fixed payment terms. The Company may decide to cancel or terminate a lease before the end of its term, in which case we are typically liable to the lessor for the remaining lease payments under the term of the lease. Additionally, all of our month-to-month leases are cancelable by the Company or the lessor, at any time, and are not included in our right-of-use asset or lease liability. As of January 1, 2021, the Company had no leases with residual value guarantees. Typically, the Company has purchase options on the equipment underlying its long-term leases. The Company may exercise some of these purchase options when the need for equipment is on-going and the purchase option price is attractive. Nonperformance-related default covenants, cross-default provisions, subjective default provisions and material adverse change clauses contained in material lease agreements, if any, are also evaluated to determine whether those clauses affect lease classification in accordance with “ASC” Topic 842-10-25. Leases are accounted for as operating or financing leases, depending on the terms of the lease. ​ Financing Leases ​ The Company leases certain equipment under financing leases. The economic substance of the leases is a financing transaction for acquisition of equipment and leasehold improvements. Accordingly, the right-of-use assets for these leases are included in the balance sheets in equipment and leasehold improvements, net of accumulated depreciation, with a corresponding amount recorded in current portion of financing lease obligations or noncurrent portion of financing lease obligations, as appropriate. The financing lease assets are amortized over the life of the lease or, if shorter, the life of the leased asset, on a straight-line basis and included in depreciation expense. The interest associated with financing lease obligations is included in interest expense. Right-of-use assets Operating leases are included in right-of-use assets, and current portion of lease liability and noncurrent portion of lease liability, as appropriate. Right-of-use assets and lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term at commencement date. As most of the Company’s leases do not provide an implicit rate to calculate present value, the Company determines this rate by estimating the Company’s incremental borrowing rate at the lease commencement date. The right-of-use asset also includes any lease payments made and initial direct costs incurred at lease commencement and excludes lease incentives. Our lease terms may include options to extend or terminate the lease when it is reasonably certain that we will exercise that option. Lease expense for minimum lease payments is recognized on a straight-line basis over the lease term. ​ The following is a summary of the lease expense: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fiscal Year ​ ​ 2020 2019 ​ ​ (in thousands) Operating lease cost ​ $ 7,031 ​ $ 5,053 Finance lease cost: ​ ​ ​ ​ ​ ​ Amortization of assets ​ ​ 589 ​ ​ 509 Interest on lease liabilities ​ ​ 29 ​ ​ 36 Total net lease cost ​ $ 7,649 ​ $ 5,598 ​ The following is a summary of lease information presented on the Company’s consolidated balance sheet: ​ ​ ​ ​ ​ ​ ​ ​ ​ January 1, ​ December 27, ​ ​ 2021 2019 ​ ​ (in thousands) ​ Operating leases: ​ ​ ​ ​ ​ ​ Right-of-use assets $ 20,130 ​ $ 22,297 ​ ​ ​ ​ ​ ​ Lease liability $ 5,844 ​ $ 5,550 ​ Lease liability, less current portion 15,649 ​ 18,411 ​ Total lease liabilities $ 21,493 ​ $ 23,961 ​ ​ ​ ​ ​ ​ Finance leases (included in equipment and leasehold improvements, net): ​ ​ ​ ​ ​ ​ Equipment and leasehold improvements, net $ 2,370 ​ $ 1,957 ​ Accumulated depreciation (1,826) ​ (1,291) ​ Total equipment and leasehold improvements, net $ 544 ​ $ 666 ​ ​ ​ ​ ​ ​ Finance lease obligations $ 248 ​ $ 375 ​ Finance lease obligations, less current portion ​ 236 ​ ​ 191 ​ Total finance lease obligations $ 484 ​ $ 566 ​ ​ ​ ​ ​ ​ ​ ​ Weighted average remaining lease term (in years): ​ ​ ​ ​ ​ ​ Operating Leases ​ 4.40 ​ ​ 4.59 ​ Finance Leases ​ 2.02 ​ ​ 1.47 ​ ​ ​ ​ ​ ​ ​ ​ Weighted average discount rate: ​ ​ ​ ​ ​ ​ Operating Leases ​ 4.44 % ​ 5.14 % Finance Leases ​ 3.74 % ​ 4.80 % ​ Rent expense for fiscal years 2020, 2019, and 2018 was $7.6 million, and $6.2 million, and $4.5 million, respectively. ​ The following is a summary of other information and supplemental cash flow information related to finance and operating leases: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fiscal Year ​ 2020 2019 ​ ​ (in thousands) Cash paid for amounts included in the measurement of lease liabilities: ​ ​ ​ ​ ​ ​ Operating cash flow from operating leases ​ $ 6,972 ​ $ 5,151 Operating cash flow from finance leases ​ ​ 29 ​ ​ 36 Financing cash flow from finance leases ​ ​ 549 ​ ​ 639 ​ ​ ​ ​ ​ ​ ​ Right-of-use assets obtained in exchange for lease liabilities: ​ ​ ​ ​ ​ ​ Operating leases ​ $ 3,186 ​ $ 4,918 ​ The following is a summary of the maturities of lease liabilities as of January 1, 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating Finance ​ ​ (in thousands) ​ Fiscal year: ​ ​ ​ ​ ​ ​ ​ 2021 ​ $ 6,645 ​ $ 261 ​ 2022 ​ 5,818 ​ 172 ​ 2023 ​ 3,983 ​ ​ 54 ​ 2024 ​ ​ 2,611 ​ ​ 14 ​ 2025 ​ ​ 2,088 ​ 2 ​ 2026 and thereafter ​ 2,489 ​ — ​ Total lease payments ​ $ 23,634 ​ $ 503 ​ Less: Imputed interest ​ (2,141) ​ ​ (19) ​ Total lease obligations ​ 21,493 ​ ​ 484 ​ Less: Current obligations ​ 5,844 ​ ​ 248 ​ Noncurrent lease obligations ​ $ 15,649 ​ $ 236 ​ ​ The imputed interest for finance lease obligations represents the interest component of finance leases that will be recognized as interest expense in future periods. The financing component for operating lease obligations represents the effect of discounting the operating lease payments to their present value. ​ ​ ​ ​

COMMITMENTS AND VARIABLE INTERE

COMMITMENTS AND VARIABLE INTEREST ENTITIES	12 Months Ended
	Jan. 01, 2021
COMMITMENTS AND VARIABLE INTEREST ENTITIES
COMMITMENTS AND VARIABLE INTEREST ENTITIES	8. COMMITMENTS AND VARIABLE INTEREST ENTITIES Employee Benefit Plans The Company has a qualified profit sharing plan pursuant to Code Section 401(a) and qualified cash or deferred arrangement pursuant to Code Section 401(k) covering all employees. Employees may elect to contribute up to 50% of their compensation limited to the amount allowed by tax laws. Company contributions are made solely at the discretion of the Company’s board of directors. The Company also had a defined contribution plan (the “Plan”) covering employees who have completed three months of service and who have attained 21 years of age. The Company elected to make matching contributions equal to 50% of the participants’ contributions to the Plan up to 6% of the individual participant’s compensation. Under the defined contribution plan, the Company may make discretionary matching contributions to employee accounts. The Company made matching contributions of $1.5 million, $2.0 million, and $1.1 million during fiscal years 2020, 2019 and 2018, respectively. Variable Interest Entities On March 4, 2016, the Company and the Company’s wholly-owned subsidiary, WES acquired substantially all of the assets of Genesys and assumed certain specified liabilities of Genesys (collectively, the “Purchase”) pursuant to an Asset Purchase and Merger Agreement, dated as of February 26, 2016 (the “Agreement”), by and among Willdan Group, Inc., WES, WESGEN (as defined below), Genesys and Ronald W. Mineo (“Mineo”) and Robert J. Braun (“Braun” and, together with Mineo, the “Genesys Shareholders”). On March 5, 2016, pursuant to the terms of the Agreement, WESGEN, Inc., a non-affiliated corporation (“WESGEN”), merged (the “Merger” and, together with the Purchase, the “Acquisition”) with Genesys, with Genesys remaining as the surviving corporation. Genesys was acquired to strengthen the Company’s power engineering capability in the northeastern U.S., and also to increase client exposure and experience with universities. Genesys continues to be a professional corporation organized under the laws of the State of New York, wholly-owned by one or more licensed engineers. Pursuant to New York law, the Company does not own capital stock of Genesys. The Company has entered into an agreement with the Shareholder of Genesys pursuant to which the Shareholder will be prohibited from selling, transferring or encumbering the Shareholder’s ownership interest in Genesys without the Company’s consent. Notwithstanding the Company’s rights regarding the transfer of Genesys’s stock, the Company does not have control over the professional decision making of Genesys’s engineering services. The Company has entered into an administrative services agreement with Genesys pursuant to which WES will provide Genesys with ongoing administrative, operational and other non-professional support services. Genesys pays WES a service fee, which consists of all of the costs incurred by WES to provide the administrative services to Genesys plus ten percent of such costs, as well as any other costs that relate to professional service supplies and personnel costs. As a result of the administrative services agreement, the Company absorbs the expected losses of Genesys through its deferral of Genesys’s service fees owed to WES. ​ The Company manages Genesys and has the power to direct the activities that most significantly impact Genesys’s performance, in addition to being obligated to absorb expected losses from Genesys. Accordingly, the Company is the primary beneficiary of Genesys and consolidates Genesys as a VIE. In addition, the Company concluded there is no noncontrolling interest related to the consolidation of Genesys because the Company determined that (i) the shareholder of Genesys does not have more than a nominal amount of equity investment at risk, (ii) WES absorbs the expected losses of Genesys through its deferral of Genesys’s service fees owed to WES and the Company has, since entering into the administrative services agreement, had to continuously defer service fees for Genesys, and (iii) the Company believes Genesys will continue to have a shortfall on payment of its service fees for the foreseeable future, leaving no expected residual returns for the shareholder. ​ As of January 1, 2021, the Company had one VIE — Genesys. ​

SEGMENT AND GEOGRAPHICAL INFORM

SEGMENT AND GEOGRAPHICAL INFORMATION	12 Months Ended
	Jan. 01, 2021
SEGMENT AND GEOGRAPHICAL INFORMATION
SEGMENT AND GEOGRAPHICAL INFORMATION	9. SEGMENT AND GEOGRAPHICAL INFORMATION Segment Information The Company’s two segments are Energy and Engineering and Consulting, and the Company’s chief operating decision maker, which continues to be its chief executive officer, receives and reviews financial information in this format. There were no intersegment sales in any of the three fiscal years ended January 1, 2021. The Company’s chief operating decision maker evaluates the performance of each segment based upon income or loss from operations before income taxes. Certain segment asset information including expenditures for long-lived assets has not been presented as it is not reported to or reviewed by the chief operating decision maker. In addition, enterprise-wide service line contract revenue is not included as it is impracticable to report this information for each group of similar services. Financial information with respect to the reportable segments and reconciliation to the amounts reported in the Company’s consolidated financial statements follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Engineering ​ Unallocated ​ ​ ​ ​ Consolidated ​ ​ Energy & Consulting Corporate Intersegment Total ​ ​ (in thousands) Fiscal Year 2020 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Contract revenue ​ $ 324,178 ​ $ 66,802 ​ $ — ​ $ — ​ $ 390,980 Depreciation and amortization ​ 17,666 ​ 1,077 ​ ​ — ​ ​ — ​ ​ 18,743 Interest expense ​ 32 ​ — ​ ​ 5,036 ​ ​ — ​ ​ 5,068 Segment profit (loss) before income tax expense ​ (9,963) ​ 9,500 ​ ​ (19,206) ​ — ​ (19,669) Income tax (benefit) expense ​ (2,621) ​ 2,499 ​ ​ (5,051) ​ — ​ ​ (5,173) Net income (loss) ​ (7,343) ​ 7,002 ​ ​ (14,155) ​ — ​ (14,496) Segment assets (1) ​ 337,739 ​ 21,796 ​ ​ 73,918 ​ (23,130) ​ 410,323 Fiscal Year 2019 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Contract revenue ​ $ 370,715 ​ $ 72,384 ​ $ — ​ $ — ​ $ 443,099 Depreciation and amortization ​ 13,703 ​ 1,324 ​ ​ — ​ ​ — ​ ​ 15,027 Interest expense ​ 32 ​ — ​ ​ 4,868 ​ ​ — ​ ​ 4,900 Segment profit (loss) before income tax expense ​ 11,971 ​ 8,839 ​ ​ (16,154) ​ — ​ 4,656 Income tax (benefit) expense ​ 3,308 ​ 2,442 ​ ​ (5,935) ​ — ​ ​ (185) Net income (loss) ​ 8,664 ​ 6,397 ​ ​ (10,220) ​ — ​ 4,841 Segment assets (1) ​ 392,362 ​ 23,682 ​ ​ 46,999 ​ (23,130) ​ 439,913 Fiscal Year 2018 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Contract revenue ​ $ 196,833 ​ $ 75,419 ​ $ — ​ $ — ​ $ 272,252 Depreciation and amortization ​ ​ 5,274 ​ 786 ​ ​ — ​ ​ — ​ ​ 6,060 Interest expense ​ ​ 312 ​ 388 ​ ​ — ​ ​ — ​ ​ 700 Segment profit before income tax expense ​ ​ 8,959 ​ 7,589 ​ ​ (4,387) ​ — ​ 12,161 Income tax expense (benefit) ​ ​ 1,570 ​ 1,330 ​ ​ (769) ​ — ​ ​ 2,131 Net income (loss) ​ ​ 7,390 ​ 6,259 ​ ​ (3,619) ​ — ​ 10,030 Segment assets (1) ​ ​ 252,124 ​ 20,402 ​ ​ 51,515 ​ (23,130) ​ 300,911 (1) Segment assets are presented net of intercompany receivables. ​ The following tables provides information about disaggregated revenue by contract type, client type and geographical region: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2020 ​ Energy Engineering and Total ​ (in thousands) Contract Type ​ ​ ​ ​ ​ ​ ​ ​ ​ Time-and-materials ​ $ 47,912 ​ $ 53,840 ​ $ 101,752 Unit-based ​ ​ 170,991 ​ ​ 9,195 ​ ​ 180,186 Fixed price ​ ​ 105,275 ​ ​ 3,767 ​ ​ 109,042 Total ​ $ 324,178 ​ $ 66,802 ​ $ 390,980 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Client Type ​ ​ ​ ​ ​ ​ ​ ​ ​ Commercial ​ $ 36,212 ​ $ 5,155 ​ $ 41,367 Government ​ ​ 93,821 ​ ​ 61,412 ​ ​ 155,233 Utilities ​ ​ 194,145 ​ ​ 235 ​ ​ 194,380 Total ​ $ 324,178 ​ $ 66,802 ​ $ 390,980 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Geography (1) ​ ​ ​ ​ ​ ​ ​ ​ ​ Domestic ​ $ 324,178 ​ $ 66,802 ​ $ 390,980 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2019 ​ Energy Engineering and Total ​ (in thousands) Contract Type ​ ​ ​ ​ ​ ​ ​ ​ ​ Time-and-materials ​ $ 18,625 ​ $ 54,560 ​ $ 73,185 Unit-based ​ ​ 272,978 ​ ​ 14,391 ​ ​ 287,369 Fixed price ​ ​ 79,112 ​ ​ 3,433 ​ ​ 82,545 Total ​ $ 370,715 ​ $ 72,384 ​ $ 443,099 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Client Type ​ ​ ​ ​ ​ ​ ​ ​ ​ Commercial ​ $ 39,311 ​ $ 4,895 ​ $ 44,206 Government ​ ​ 57,020 ​ ​ 67,049 ​ ​ 124,069 Utilities ​ ​ 274,384 ​ ​ 440 ​ ​ 274,824 Total ​ $ 370,715 ​ $ 72,384 ​ $ 443,099 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Geography (1) ​ ​ ​ ​ ​ ​ ​ ​ ​ Domestic ​ $ 370,715 ​ $ 72,384 ​ $ 443,099 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2018 ​ Energy Engineering and Total ​ (in thousands) Contract Type ​ ​ ​ ​ ​ ​ ​ ​ ​ Time-and-materials ​ $ 13,790 ​ $ 59,744 ​ $ 73,534 Unit-based ​ ​ 113,749 ​ ​ 13,300 ​ ​ 127,049 Fixed price ​ ​ 69,294 ​ ​ 2,375 ​ ​ 71,669 Total ​ $ 196,833 ​ $ 75,419 ​ $ 272,252 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Client Type ​ ​ ​ ​ ​ ​ ​ ​ ​ Commercial ​ $ 20,715 ​ $ 4,882 ​ $ 25,597 Government ​ ​ 62,897 ​ ​ 70,091 ​ ​ 132,988 Utilities ​ ​ 113,221 ​ ​ 446 ​ ​ 113,667 Total ​ $ 196,833 ​ $ 75,419 ​ $ 272,252 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Geography (1) ​ ​ ​ ​ ​ ​ ​ ​ ​ Domestic ​ $ 196,833 ​ $ 75,419 ​ $ 272,252 (1) Revenue from our foreign operations were immaterial for fiscal years 2020 and 2019. For fiscal year 2018, we did not have any foreign revenues. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2020 2019 ​ ​ (in thousands) Assets: ​ ​ ​ ​ ​ ​ Cash and cash equivalents ​ $ 28,405 ​ $ 5,452 Accounts Receivable, net ​ ​ (4,845) ​ ​ (108) Prepaid expenses ​ 2,422 ​ 1,912 Intercompany receivables ​ 691,440 ​ 125,126 Goodwill ​ ​ 2 ​ ​ 2 Other receivables ​ 4,409 ​ 3,915 Equipment and leasehold improvements, net ​ 1,585 ​ 1,637 Investments in subsidiaries ​ 26,576 ​ 23,130 ROU Assets ​ ​ 809 ​ ​ 1,141 Other ​ 444 ​ 606 Deferred income taxes ​ ​ 14,111 ​ ​ 9,312 ​ ​ $ 765,358 ​ $ 172,125 ​ Geographical Information ​ Substantially all of the Company’s consolidated revenue was derived from its operations in the U.S. In connection with the Company’s acquisition of E3, Inc. in October 28, 2019, the Company expanded its operations into Canada. Revenues from the Company’s Canadian operations were not material for fiscal years 2020 and 2019. Customer Concentration For fiscal years 2020, 2019, and 2018, the Company’s top 10 customers accounted for 48.0%, 50.6%, and 56.9%, respectively, of the Company’s consolidated contract revenue. During fiscal years 2020, 2019, and 2018, the Company had individual customers that accounted for more than 10% of its consolidated contract revenues. For fiscal year 2020, the Company derived 10.2% of its consolidated contract revenue from one customer, Los Angeles Department of Water and Power. For fiscal year 2019, the Company derived 29.1% of its consolidated contract revenue from two customers, Consolidated Edison of New York and the Los Angeles Department of Water and Power. For fiscal year 2018, the Company derived 19.0% of its consolidated contract revenue from one customer, Consolidated Edison of New York. On a segment basis, the Company also had individual customers that accounted for more than 10% of its segment contract revenues. For fiscal year 2020, the Company derived 22.5% of its Energy segment revenues from two customers, Los Angeles Department of Water and Power and The Dormitory Authority State of New York (“DASNY”), and it derived 18.2% of its Engineering and Consulting segment revenues from one customer, the City of Elk Grove. For fiscal year 2019, the Company derived 34.7% of its Energy segment revenues from two customers, Consolidated Edison of New York and the Los Angeles Department of Water and Power, and it derived 25.0% of its Engineering and Consulting segment revenues from one customer, the City of Elk Grove. For 2018, the Company derived 18.5% of its Energy segment revenues from one customer, Consolidated Edison of New York, and it derived 10% of its Engineering and Consulting segment revenues from three customers, the City of Elk Grove, City of Long Beach and Ygrene. The Company’s largest clients are based in California and New York. In fiscal year 2020, 2019, and 2018, services provided to clients in California accounted for 37.0%, 41.1%, and 35.0%, respectively, of the Company’s contract revenue and services provided to clients in New York accounted for 19.2%, 27.2%, and 29.0%, respectively, of the Company’s contract revenue.

SHAREHOLDERS' EQUITY

SHAREHOLDERS' EQUITY	12 Months Ended
	Jan. 01, 2021
SHAREHOLDERS' EQUITY
SHAREHOLDERS' EQUITY	10. SHAREHOLDERS’ EQUITY Stock Incentive Plans ​ As of January 1, 2021, the Company had two share-based compensation plans, which are described below. The Company may no longer grant awards under the 2006 Stock Incentive Plan. ​ 2006 Stock Incentive Plan In June 2006, the Company’s board of directors adopted the 2006 Stock Incentive Plan (“2006 Plan”) and it received stockholder approval. The Company re-submitted the 2006 Plan to its stockholders for post-IPO approval at the 2007 annual meeting of the stockholders and it was approved. The 2006 Plan terminated in June 2016 and no additional awards were granted under the 2006 Plan after the Company’s shareholders approved the 2008 Plan (as defined below) in June 2008. The 2006 Plan had 300,000 shares of common stock reserved for issuance to the Company’s directors, executives, officers, employees, consultants and advisors. Approximately 70,333 shares that were available for award grant purposes under the 2006 Plan have become available for grant under the 2008 Plan following shareholder approval of the 2008 Plan. Options granted under the 2006 Plan could be “non-statutory stock options” which expire no more than 10 years from the date of grant or “incentive stock options” as defined in Section 422 of the Internal Revenue Code of 1986, as amended (the “Internal Revenue Code”). Upon exercise of non-statutory stock options, the Company is generally entitled to a tax deduction on the exercise of the option for an amount equal to the excess over the exercise price of the fair market value of the shares at the date of exercise. The Company is generally not entitled to any tax deduction on the exercise of an incentive stock option. As of January 1, 2021, there were no outstanding stock options under the 2006 Plan. Amended and Restated 2008 Performance Incentive Plan In March 2008, the Company’s board of directors adopted the 2008 Performance Incentive Plan (“2008 Plan”), and it received stockholder approval at the 2008 annual meeting of the stockholders in June 2008. The 2008 Plan was originally set to terminate on April 17, 2027 but received a ten-year extension at the 2019 annual meeting of the stockholders. The 2008 Plan is currently scheduled to expire on April 18, 2029. The 2008 Plan initially had 450,000 shares of common stock reserved for issuance (not counting any shares originally available under the 2006 Plan that “poured over.”) At the 2010, 2012, 2016, 2017, 2019 annual meetings of the stockholders, the stockholders approved 350,000, 500,000, 500,000, 875,000 and 955,000 share increases, respectively, to the 2008 Plan. The maximum number of shares of the Company’s common stock that may be issued or transferred pursuant to awards under the 2008 Plan can also be increased by any shares subject to stock options granted under the 2006 Plan and outstanding as of June 9, 2008 which expire, or for any reason are cancelled or terminated, after June 9, 2008 without being exercised. The 2008 Plan currently has 161,000 shares of common stock reserved for issuance. Awards authorized by the 2008 Plan include stock options, stock appreciation rights, restricted stock, stock bonuses, stock units, performance stock, and other share-based awards. No participant may be granted an option to purchase more than 300,000 shares in any fiscal year. Options generally may not be granted with exercise prices less than fair market value at the date of grant, with vesting provisions and contractual terms determined by the compensation committee of the board of directors on a grant-by-grant basis, subject to the minimum vesting provisions contained in the 2008 Plan. Options granted under the 2008 Plan may be “nonqualified stock options” or “incentive stock options” as defined in Section 422 of the Internal Revenue Code. The maximum term of each option shall be 10 years. Upon exercise of nonqualified stock options, the Company is generally entitled to a tax deduction on the exercise of the option for an amount equal to the excess over the exercise price of the fair market value of the shares at the date of exercise. The Company is generally not entitled to any tax deduction on the exercise of an incentive stock option. For awards other than stock options, the Company is generally entitled to a tax deduction at the time the award holder recognizes income with respect to the award equal to the amount of compensation income recognized by the award holder. Options and other awards provide for accelerated vesting if there is a change in control (as defined in the 2008 Plan) and the outstanding awards are not substituted or assumed in connection with the transaction. Through January 1, 2021, outstanding awards granted, net of forfeitures and exercises, under the 2008 Plan consisted of 65,000 shares of incentive stock options, 938,000 shares of non-statutory stock options, 128,000 shares of restricted stock awards and 380,000 shares of performance-based restricted stock units. Employee Stock Purchase Plan Amended and Restated 2006 Employee Stock Purchase Plan The Company adopted its Amended and Restated 2006 Employee Stock Purchase Plan (“ESPP”) to allow eligible employees the right to purchase shares of common stock, at semi-annual intervals, with their accumulated payroll deductions. The plan received stockholder approval in June 2006. The Company re-submitted the plan to its stockholders for post-IPO approval at the 2007 annual stockholders’ meeting where approval was obtained. The ESPP initially had 300,000 shares of common stock reserved for issuance. At the 2017 annual meeting of the stockholders, the stockholders approved an 825,000 share increase to the ESPP. A total of 1,125,000 shares of the Company’s common stock have been reserved for issuance under the plan. The plan has semi-annual periods beginning on each January 1 and ending on each June 30 and beginning on each July 1 and ending on each December 31. The first offering period commenced on February 10, 2007 and ended on June 30, 2007. Participants make contributions under the plan only by means of payroll deductions each payroll period. The rate of payroll contributions elected by a Participant may not be less than one percent (1%) nor more than ten percent (10%) of the Participant’s Earnings for each payroll period, and only whole percentages may be elected. The accumulated contributions are applied to the purchase of shares. Shares are purchased under the plan on or as soon as practicable after, the last day of the offering period. The purchase price per share equals 85% of the fair market value of a share on the lesser price of the share on the first day or last day of the offering period. The Company’s Amended and Restated 2006 Employee Stock Purchase Plan is a compensatory plan. As of January 1, 2021, there were 519,000 shares available for issuance under the plan. Stock-based Compensation Expense The compensation expense that has been recognized for stock options, restricted stock awards (“RSA”), performance-based restricted stock units (“PBRSU”), and ESPP issued under these plans was $16.7 million, $12.1 million, and $6.3 million for fiscal years 2020, 2019, and 2018, respectively. ​ The total unrecognized compensation expense related to nonvested stock options was $0.4 million, $1.5 million, and $3.6 million for fiscal years 2020, 2019, and 2018, respectively. The total unrecognized compensation expense related to RSAs was $3.6 million, $1.5 million, and $1.0 million for fiscal years 2020, 2019, and 2018, respectively. The total unrecognized compensation expense related to PBRSUs was $13.2 million, $21.5 million, and $12.3 million for the fiscal years 2020, 2019, and 2018, respectively. That expense is expected to be recognized over a weighted-average period of 0.61 years. There were no options granted that were immediately vested during the fiscal years 2020, 2019, or 2018. Summary of Stock Option Activity A summary of option activity under the 2006 Plan and 2008 Plan as of January 1, 2021 and changes during the fiscal years ended January 1, 2021, December 27, 2019 and December 28, 2018 is presented below. The intrinsic value of the fully-vested options is $22.9 million based on the Company’s closing stock price of $41.70 and the average exercise price of outstanding options on January 1, 2021. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted- ​ ​ ​ ​ Weighted- ​ Average ​ ​ ​ ​ Average ​ Remaining ​ ​ ​ ​ Exercise ​ Contractual ​ Options Price Term ​ ​ (in thousands) ​ ​ ​ ​ (in years) ​ Outstanding at December 27, 2019 1,124 ​ $ 17.80 6.06 ​ Granted — ​ — — ​ Exercised (119) ​ 9.12 — ​ Forfeited or expired (2) ​ 2.71 — ​ Outstanding at January 1, 2021 1,003 ​ $ 18.86 5.43 ​ Vested and expected to vest at January 1, 2021 1,003 ​ $ 18.86 5.43 ​ Exercisable at January 1, 2021 952 ​ $ 18.16 5.31 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted- ​ ​ ​ ​ ​ Weighted- ​ Average ​ ​ ​ ​ Average ​ Remaining ​ ​ ​ ​ Exercise ​ Contractual ​ Options Price Term ​ ​ (in thousands) ​ ​ ​ ​ (in years) ​ Outstanding at December 28, 2018 1,252 ​ $ 16.87 6.62 ​ Granted — ​ — — ​ Exercised (115) ​ 8.08 — ​ Forfeited or expired (13) ​ 14.97 — ​ Outstanding at December 27, 2019 1,124 ​ $ 17.80 6.06 ​ Vested and expected to vest at December 27, 2019 1,124 ​ $ 17.80 6.06 ​ Exercisable at December 27, 2019 958 ​ $ 15.48 5.68 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted- ​ ​ ​ ​ Weighted- ​ Average ​ ​ ​ ​ Average ​ Remaining ​ ​ ​ ​ Exercise ​ Contractual ​ Options Price Term ​ ​ (in thousands) ​ ​ ​ ​ (in years) ​ Outstanding at December 29, 2017 1,207 ​ $ 14.04 7.02 ​ Granted 158 ​ 31.54 — ​ Exercised (85) ​ 7.85 — ​ Forfeited or expired (28) ​ 5.07 — ​ Outstanding at December 28, 2018 1,252 ​ $ 16.87 6.62 ​ Vested and expected to vest at December 28, 2018 1,252 ​ $ 16.87 6.62 ​ Exercisable at December 28, 2018 838 ​ $ 12.20 5.58 ​ ​ A summary of the status of the Company’s nonvested options and changes in nonvested options is presented below: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted- ​ ​ ​ ​ Average ​ ​ ​ ​ Grant-Date ​ Options Fair Value ​ ​ (in thousands) ​ ​ ​ ​ Nonvested at December 27, 2019 166 ​ $ 12.15 ​ Granted — ​ — ​ Vested (114) ​ 30.97 ​ Forfeited — ​ — ​ Nonvested at January 1, 2021 52 ​ 31.73 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted- ​ ​ ​ ​ ​ Average ​ ​ ​ ​ Grant-Date ​ Options Fair Value ​ ​ (in thousands) ​ ​ ​ ​ Nonvested at December 28, 2018 414 ​ $ 8.69 ​ Granted — ​ — ​ Vested (242) ​ 9.43 ​ Forfeited (6) ​ 10.87 ​ Nonvested at December 27, 2019 166 ​ 12.15 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted- ​ ​ ​ ​ ​ Average ​ ​ ​ ​ Grant-Date ​ Options Fair Value ​ ​ (in thousands) ​ ​ ​ ​ Nonvested at December 29, 2017 547 ​ $ 6.43 ​ Granted 158 ​ 12.73 ​ Vested (263) ​ 7.29 ​ Forfeited (28) ​ 5.07 ​ Nonvested at December 28, 2018 414 ​ 8.69 ​ ​ Summary of Restricted Stock Activity A summary of restricted stock activity under the 2008 Plan as of January 1, 2021 is presented below: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted- ​ ​ ​ ​ Average ​ Restricted Stock Grant Date ​ ​ (in thousands) ​ ​ ​ ​ Outstanding at December 27, 2019 ​ 58 ​ $ 33.33 Awarded ​ 99 ​ 32.89 ​ Vested ​ (29) ​ 32.35 ​ Forfeited ​ — ​ — ​ Outstanding at January 1, 2021 ​ 128 ​ $ 33.21 ​ ​ ​ ​ ​ ​ ​ ​ Outstanding at December 28, 2018 ​ 64 ​ $ 22.28 Awarded ​ 37 ​ 35.60 ​ Vested ​ (43) ​ 18.90 ​ Forfeited ​ — ​ — ​ Outstanding at December 27, 2019 ​ 58 ​ $ 33.33 ​ ​ ​ ​ ​ ​ ​ ​ Outstanding at December 29, 2017 ​ 87 ​ $ 17.67 ​ Awarded ​ 22 ​ 28.17 ​ Vested ​ (45) ​ 16.09 ​ Forfeited ​ — ​ — ​ Outstanding at December 28, 2018 ​ 64 ​ $ 22.28 ​ ​ Summary of Performance-Based Restricted Stock Unit Activity A summary of performance-based restricted stock unit activity under the 2008 Plan as of January 1, 2021 is presented below: ​ ​ ​ ​ ​ ​ ​ ​ ​ Performance-Based ​ Weighted-Average ​ Restricted Stock Unit Grant Date Fair Value ​ ​ (in thousands) ​ ​ ​ Outstanding at December 27, 2019 ​ 431 ​ $ 20.68 Awarded ​ 413 ​ 29.22 Released ​ (447) ​ 28.26 Forfeited ​ (18) ​ 28.62 Outstanding at January 1, 2021 ​ 379 ​ $ 20.68 ​ ​ ​ ​ ​ ​ Outstanding at December 28, 2018 ​ 280 ​ $ 21.94 Awarded ​ 329 ​ 28.99 Released ​ (175) ​ 38.20 Forfeited ​ (3) ​ 27.28 Outstanding at December 27, 2019 ​ 431 ​ $ 20.68 ​ ​ ​ ​ ​ ​ Outstanding at December 28, 2018 ​ — ​ $ — Awarded ​ 280 ​ 21.94 Released ​ — ​ — Forfeited ​ — ​ — Outstanding at December 27, 2019 ​ 280 ​ $ 21.94 ​ Fair Value Valuation Assumptions Stock Option Grants The fair value of each option is calculated using the Black-Scholes option valuation model that uses the assumptions noted in the following table. Expected volatility is based upon historical volatility of “guideline companies” since the length of time the Company’s shares have been publicly traded is equal to the contractual term of the options. The expected term of the option, taking into account both the contractual term of the option and the effects of employees’ expected exercise and expected post-vesting termination behavior is estimated based upon the simplified method. Under this approach, the expected term is presumed to be the mid-point between the vesting date and the end of the contractual term. The risk-free rate for periods within the contractual life of the option is based on the U.S. Treasury yield curve in effect at the time of grant. No options were granted during fiscal year 2020. The fair value of stock options granted in fiscal years 2019 and 2018 was estimated using the following assumptions: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2019 2018 Expected volatility 34 % 37 % - 38 % Expected dividends 0 % ​ ​ ​ 0 % Expected term (in years) 6 ​ ​ ​ ​ 6 ​ Risk-free rate 2.49 % 2.65 % - 2.78 % ​ RSA and PBRSU Grants The Company’s restricted stock awards are valued on the closing price of the Company’s common stock on the date of grant and typically vest over a three-year period. The Company’s performance-based restricted stock unit awards are valued on the closing price of the Company’s common stock on the date of grant and vest over performance period. Under the Company’s new performance-based restricted stock unit (“PBRSU”) design, 50% of each award will vest based upon the Company’s EBITDA performance over a two-year and four-year performance periods (“EBITDA Units”), and the remaining 50% of each award will vest based upon the Company’s earnings per share performance over a two-year and four-years -performance periods (“EPS Units”) for awards granted for 2019 and 2018, respectively. The Company must achieve a 10% growth rate for the threshold number of EBITDA Units and EPS Units to vest for any performance year, and the target number of EBITDA Units and EPS Units will only vest in any performance year if the Company is able to achieve a 20% growth rate. The Compensation Committee determined to move away from its historical practice of granting only time-based equity awards and introduced the PBRSUs in order to further align the interests of the Company’s executives with those of shareholders by strengthening the relationship between executive pay and the Company’s performance against two critical performance metrics that the Company believes will drive value creation for its shareholders. ESPP The fair value of ESPP purchase rights issued is calculated using the Black-Scholes valuation model that uses the assumptions noted in the following table. Purchase right under the ESPP are generally granted on either January 1 or July 1 of each year. The assumptions are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2020 ​ ​ 2019 ​ ​ 2018 ​ Weighted-average expected term (in years) ​ .5 ​ ​ ​ .5 ​ ​ ​ .5 ​ Risk-Free interest Rate ​ 0.9 % ​ ​ 2.3 % ​ ​ 1.4 % Stock Price Volatility ​ 30.3 % ​ ​ 35.6 % ​ ​ 37.9 % Dividend yield ​ 0 % ​ ​ 0 % ​ ​ 0 % Fair Value ​ $ 28.39 ​ ​ $ 33.01 ​ ​ $ 26.86 ​ ​

INCOME TAXES

INCOME TAXES	12 Months Ended
	Jan. 01, 2021
INCOME TAXES
INCOME TAXES	11. INCOME TAXES The provision for income taxes is comprised of (1) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fiscal Year ​ 2020 2019 2018 ​ ​ (in thousands) ​ Current federal taxes ​ $ (592) ​ $ (548) ​ $ 3,632 ​ Current state taxes ​ 166 ​ 551 ​ 1,389 ​ Current foreign taxes ​ ​ 18 ​ ​ — ​ ​ — ​ Deferred federal taxes ​ (2,939) ​ (159) ​ (2,539) ​ Deferred state taxes ​ (1,826) ​ (29) ​ (351) ​ ​ ​ $ (5,173) ​ $ (185) ​ $ 2,131 ​ ​ (1) Revenue from the Company’s foreign operations were immaterial for fiscal years 2020 and 2019. For fiscal year 2018, the Company did not have any foreign revenues The provision for income taxes reconciles to the amounts computed by applying the statutory federal tax rate of 21% for fiscal years 2020, 2019 and 2018 to the Company’s income before income taxes. The sources and tax effects of the differences for fiscal years 2020, 2019, and 2018 are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2020 2019 2018 ​ ​ (in thousands) ​ Computed “expected” federal income tax expense ​ $ (4,130) ​ $ 977 ​ $ 2,554 ​ Permanent differences ​ 122 ​ 163 ​ 77 ​ Nondeductible Executive Compensation ​ ​ 1,386 ​ ​ 688 ​ ​ — ​ Stock options and disqualifying dispositions ​ ​ 4 ​ ​ (731) ​ ​ (354) ​ Energy efficient building deduction ​ ​ (738) ​ ​ (1,291) ​ ​ (919) ​ Current and deferred state income tax expense, net of federal benefit ​ (1,205) ​ 466 ​ 815 ​ Federal deferred tax adjustments ​ ​ — ​ ​ 231 ​ ​ 220 ​ Adjustment for uncertain tax positions ​ ​ (142) ​ ​ (282) ​ ​ 61 ​ Research and development tax credit ​ ​ (527) ​ ​ (510) ​ ​ (313) ​ Adjustment to prior earn-out liability ​ ​ — ​ ​ — ​ ​ (198) ​ Non-deductible transaction expenses ​ ​ — ​ ​ — ​ ​ 203 ​ Other ​ 57 ​ 27 ​ (15) ​ True up income tax accounts ​ ​ — ​ ​ 77 ​ ​ — ​ ​ ​ $ (5,173) ​ $ (185) ​ $ 2,131 ​ ​ Differences between the Company’s effective income tax rate and what would be expected if the federal statutory rate was applied to income before income tax from continuing operations are primarily due to state income tax expense, research and development tax credits, energy efficient building deductions, stock options and disqualifying dispositions. The tax effects of temporary differences that give rise to significant portions of the net deferred tax assets and liabilities are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ January 1, ​ December 27, ​ 2021 2019 ​ ​ (in thousands) Deferred tax assets: ​ ​ ​ ​ ​ ​ Accounts receivable allowance ​ $ 199 ​ $ 315 Other accrued liabilities ​ ​ 1,676 ​ ​ 2,124 Federal and state net operating losses ​ ​ 18,854 ​ ​ 18,717 Lease Liability ​ ​ 5,856 ​ ​ 6,467 Stock compensation ​ ​ 3,063 ​ ​ 3,381 Adjustments to fair value of assets ​ ​ 56 ​ ​ 79 Credit Carryforwards ​ ​ 496 ​ ​ — Other ​ 211 ​ 622 ​ ​ 30,411 ​ 31,705 Valuation allowance ​ (86) ​ (86) Net deferred tax assets ​ $ 30,325 ​ $ 31,619 Deferred tax liabilities: ​ ​ ​ ​ ​ ​ Deferred revenue ​ $ (2,999) ​ $ (5,031) Fixed assets ​ ​ (732) ​ ​ (618) Intangible assets ​ ​ (6,796) ​ ​ (10,077) Lease right-of-use assets ​ ​ (5,484) ​ ​ (6,127) Other ​ ​ (203) ​ ​ (454) ​ ​ (16,214) ​ (22,307) Net deferred tax asset ​ $ 14,111 ​ $ 9,312 ​ At January 1, 2021, the Company had federal and state operating loss carryovers of $72.2 million and $59.2 million, respectively. The carryovers expire through 2040. During each fiscal year, management assesses the available positive and negative evidence to estimate if sufficient future taxable income will be generated to utilize existing deferred tax assets. For fiscal years 2020 and 2019, the Company ultimately determined that it was more-likely-than-not that the entire California net operating loss will not be utilized prior to expiration. Significant pieces of objective evidence evaluated included the Company’s history of utilization of California net operating losses in prior years for each of the Company’s subsidiaries, as well as the Company’s forecasted amount of net operating loss utilization for certain members of the combined group. As of January 1, 2021 and December 27, 2019, the Company had a valuation allowance in the amount of $86,000, respectively, related to California net operating losses. During the fiscal year 2020, the Company removed its recorded liability for uncertain tax positions due to the expiration of federal and state statute of limitations during fiscal year 2020. This decrease resulted from the expiration of federal uncertain tax positions during fiscal year 2019. The Company may be subject to examination by the Internal Revenue Service (“IRS”) for calendar years 2017 through 2020. The Company may also be subject to examination on certain state and local jurisdictions for the years 2016 through 2020. The Company's policy is to recognize interest and penalties related to unrecognized tax benefits in income tax expense. The following is a reconciliation of beginning and ending amounts of unrecognized tax benefits: ​ ​ ​ ​ ​ ​ Amount ​ ​ (in thousands) Balance as of December 27, 2019 ​ $ 142 Additions based on tax positions related to the current year ​ — Additions for tax positions of prior years ​ ​ — Reductions for tax positions related to the current year ​ ​ — Reductions for tax positions of prior years ​ ​ (142) Balance as of January 1, 2021 ​ $ — ​ During the year ended January 1, 2021, the Internal Revenue Service finalized its audit of the Company’s tax return for the fiscal year ended December 30, 2016. There were no changes made by the Internal Revenue Service to the tax return filed. ​ On March 27, 2020, President Trump signed into law the Coronavirus Aid, Relief, and Economic Security (CARES) Act (H.R. 748) which includes a number of provisions relating to refundable payroll tax credits, deferment of employer side social security payments, net operating loss carryback periods, alternative minimum tax credit refunds, modifications to the net interest deduction limitations and technical corrections to tax depreciation methods for qualified improvement property. Under ASC 740, the effects of new legislation are recognized upon enactment. Accordingly, the effects of the CARES Act have been incorporated into the income tax provision computation for the fiscal year ended January 1, 2021. These provisions did not have a material impact on the income tax provision. ​ On December 27, 2020, President Trump signed into law the Consolidated Appropriations Act, 2021 (CAA 2021) which included a number of provisions including, but not limited to the extension of numerous employment tax credits, the extension of the Section 179D deduction, enhanced business meals deductions, and the deductibility of expenses paid for with Paycheck Protection Program (PPP) loan funds that are forgiven. Accordingly, the effects of the CCA have been incorporated into the income tax provision computation for the fiscal year ended January 1, 2021. The extension of the energy efficiency building deduction under Section 179D resulted in the continuation of this additional benefit for the Company. ​

EARNINGS PER SHARE (EPS)

EARNINGS PER SHARE (EPS)	12 Months Ended
	Jan. 01, 2021
EARNINGS PER SHARE (EPS)
EARNINGS PER SHARE (EPS)	12. EARNINGS PER SHARE (“EPS”) Basic EPS is computed by dividing net income available to common stockholders by the weighted-average number of common shares outstanding. Diluted EPS is computed by dividing net income by the weighted-average number of common shares outstanding and dilutive potential common shares for the period. Potential common shares include the weighted-average dilutive effects of outstanding stock options and restricted stock awards using the treasury stock method. The following table sets forth the number of weighted-average common shares outstanding used to compute basic and diluted EPS: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fiscal Year ​ ​ 2020 2019 2018 ​ ​ (in thousands, except per share amounts) Net income (loss) ​ $ (14,496) ​ $ 4,841 ​ $ 10,030 Weighted-average common shares outstanding ​ 11,793 ​ 11,162 ​ 9,264 Effect of dilutive stock options and restricted stock awards ​ — ​ 604 ​ 499 Weighted-average common shares outstanding-diluted ​ 11,793 ​ 11,766 ​ 9,763 Earnings (Loss) per share: ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic ​ $ (1.23) ​ $ 0.43 ​ $ 1.08 Diluted ​ $ (1.23) ​ $ 0.41 ​ $ 1.03 ​ For the fiscal year 2020, the Company reported a net loss, and accordingly, all outstanding equity awards have been excluded because including them would have been anti-dilutive. For the fiscal year ended December 27, 2019, 155,300 options were excluded from the calculation of dilutive potential common shares, compared to 247,800 options, for 2018. These options were not included in the computation of dilutive potential common shares because the assumed proceeds per share exceeded the average market price per share for the respective periods. Accordingly, the inclusion of these options would have been anti-dilutive. ​

BUSINESS COMBINATIONS

BUSINESS COMBINATIONS	12 Months Ended
	Jan. 01, 2021
BUSINESS COMBINATIONS
BUSINESS COMBINATIONS	13. BUSINESS COMBINATIONS Acquisition of E3, Inc. ​ On October 28, 2019, the Company, through its wholly-owned subsidiary WES, acquired all of the capital stock of Energy and Environmental Economics, Inc. (“E3, Inc.”), pursuant to the terms of a stock purchase agreement (the “Stock Purchase Agreement”) by and among the Company, WES, E3, Inc., each of the stockholders of E3, Inc. (the “E3, Inc. Stockholders”) and Ren Orans, as seller representative of the E3, Inc. Stockholders. E3, Inc. is an energy consulting firm that helps utilities, regulators, policy makers, developers, and investors make strategic decisions as they implement new public policies, respond to technological advances, and address customers’ shifting expectations in clean energy. The Company believes that E3 will provide Willdan and our clients visibility into future market trends and position us to advise clients on upcoming policy, electrification, and decarbonization. E3, Inc.’s financial information is included within the Energy segment beginning in the fourth quarter of fiscal year 2019. The Company finalized the purchase price allocation with respect to this transaction during the fourth quarter of fiscal 2020. The Company agreed to pay up to $44.0 million for the purchase of all of the capital stock of E3, Inc., which purchase price consists of (i) $27.0 million in cash paid on the E3, Inc. Closing Date (subject to holdbacks and adjustments), (ii) $5.0 million in shares of the Company’s common stock, based on the volume-weighted average price per share of the Company’s common stock for the ten trading days immediately following, but not including, the E3, Inc. Closing Date and (iii) up to $12.0 million in cash if E3, Inc. exceeds certain financial targets during the three years after the E3, Inc. Closing Date, as more fully described below (such potential payments of up to $12.0 million, being referred to as “Earn-Out Payments” and $12.0 million in respect thereof, being referred to as the “Maximum Payout”). The amount of the Earn-Out Payments to be paid will be determined based on E3, Inc.’s earnings before interest, taxes, depreciation and amortization (“EBITDA”). The E3, Inc. Stockholders will receive Earn-Out Payments in each of the three years after the E3, Inc. Closing Date (the “Earn-Out Period”) based on the amount by which E3, Inc.’s EBITDA exceeds certain targets . The amounts due to the E3, Inc. Stockholders as Earn-Out Payments will in no event, individually or in the aggregate, exceed the Maximum Payout. Earn-Out Payments will be made in annual installments for each of the three years of the Earn-Out Period. In addition, the Earn-Out Payments will be subject to certain subordination provisions in favor of the lenders under the Company’s Credit Agreement. The Purchase Agreement also contains customary representations and warranties regarding WES, the Company, E3, Inc. and the E3, Inc. Stockholders, indemnification provisions and other provisions customary for transactions of this nature. The Company borrowed $30.0 million under its Delayed Draw Term Loan on October 28, 2019 to fund the $27.0 million cash payment paid on the E3, Inc. Closing Date. The acquisition was accounted for as a business combination in accordance with ASC 805. Under ASC 805, the Company recorded the acquired assets and assumed liabilities at their estimated fair value with the excess allocated to goodwill. Goodwill represents the value the Company expects to achieve through the operational synergies, the expansion into new markets and the acquired company’s assembled work force. The Company estimates that the entire $21.8 million of goodwill resulting from the acquisition will be tax deductible. Consideration for the acquisition includes the following: ​ ​ ​ ​ ​ ​ E3, Inc. ​ ​ ​ (in thousands) Cash paid ​ $ 27,000 Other working capital adjustment ​ ​ 1,780 Issuance of common stock ​ ​ 5,000 Contingent Consideration ​ ​ 6,000 Total consideration ​ $ 39,780 ​ The following table summarizes the amounts for the acquired assets recorded at their estimated fair value as of the acquisition date: ​ ​ ​ ​ ​ ​ E3, Inc. ​ ​ ​ (in thousands) Current assets ​ $ 5,278 Non-current assets (1) ​ ​ 341 Cash ​ ​ 2,264 Equipment and leasehold improvements, net ​ ​ 409 Right-of-use assets ​ ​ 7,641 Current lease liability ​ ​ (750) Non-current lease liability ​ ​ (6,890) Liabilities ​ ​ (4,325) Backlog ​ ​ 2,600 Customer relationships ​ ​ 6,050 Tradename ​ ​ 4,200 Developed technology ​ ​ 880 In-progress research & development ​ ​ 310 Goodwill ​ ​ 21,772 Net assets acquired ​ $ 39,780 (1) Excluded from non-current assets are equipment and leasehold improvements, net, right-of-use assets, customer relationships, tradename, backlog and goodwill. During the fiscal year 2020, the Company made adjustments, primarily related to other working capital and contingent consideration, to the consideration paid for E3, Inc. which resulted in an adjustment to the purchase price allocation of E3, Inc. The adjustments resulted in an aggregate increase of $5.1 million in the net carrying value of right of use assets, non-current lease liability, backlog, tradename, developed technology, and in-progress research and development, and an aggregate decrease of $4.5 million in the net carrying value of current assets, current lease liability, liabilities, customer relationships, non-compete, and goodwill. The change in the fair value of intangible assets resulted in a decrease in the amortization expense of $0.1 million for the fiscal year ended January 1, 2021. The acquisition related costs associated with E3, Inc. included in other general and administrative expenses in the consolidated statements of comprehensive income were not material for the year ended January 1, 2021. During fiscal year 2020, the acquisition of E3, Inc. contributed $23.2 million in revenue and $4.3 million of income from operations. Acquisition of Onsite Energy Corporation ​ On July 2, 2019, the Company acquired substantially all of the assets and liabilities of Onsite Energy Corporation (“Onsite Energy”), an energy efficiency services and project implementation firm that specializes in energy upgrades and commissioning for industrial facilities. The Company believes the acquisition will expand its presence in the California-based industrial energy management services. Pursuant to the terms of the Asset Purchase Agreement, dated July 2, 2019, by and between WES and Onsite Energy, WES will pay a maximum aggregate purchase price of $26.4 million, subject to certain holdback and working capital adjustments, to be paid in cash. Onsite Energy’s financial information is included within the Energy segment. The Company finalized the purchase price allocation with respect to this transaction during the second quarter of fiscal year 2020. The acquisition was accounted for as a business combination in accordance with ASC 805. Under ASC 805, the Company recorded the acquired assets and assumed liabilities at their estimated fair value with the excess allocated to goodwill. Goodwill represents the value the Company expects to achieve through the operational synergies, the expansion into new markets and the acquired company’s assembled work force. The Company estimates that the entire $8.6 million of goodwill resulting from the acquisition will be tax deductible. Consideration for the acquisition includes the following: ​ ​ ​ ​ ​ ​ Onsite Energy ​ ​ ​ (in thousands) Cash paid ​ $ 24,905 Other working capital adjustment ​ ​ - Total consideration ​ $ 24,905 ​ ​ ​ ​ ​ The following table summarizes the amounts for the acquired assets recorded at their estimated fair value as of the acquisition date: ​ ​ ​ ​ ​ ​ Onsite Energy ​ ​ ​ (in thousands) Current assets ​ $ 19,058 Non-current assets (1) ​ ​ 10 Equipment and leasehold improvements, net ​ ​ 39 Right-of-use assets ​ ​ 828 Current lease liability ​ ​ (168) Non-current lease liability ​ ​ (660) Liabilities ​ ​ (12,222) Backlog ​ ​ 1,510 Customer relationships ​ ​ 7,050 Tradename ​ ​ 860 Goodwill ​ ​ 8,600 Net assets acquired ​ $ 24,905 (1) Excluded from non-current assets are equipment and leasehold improvements, net, right-of-use assets, customer relationships, tradename, backlog and goodwill. During fiscal year 2020, the Company made adjustments, primarily related to other working capital, to the consideration paid for Onsite Energy which resulted in an adjustment to the purchase price allocation of Onsite Energy. The adjustments resulted in an aggregate increase of $3.5 million in the net carrying value of backlog, tradename and goodwill and an aggregate decrease of $3.5 million in the net carrying value of current assets and goodwill. The adjustment in the fair value of intangible assets resulted in a $0.7 million change of the amortization expense for the year ended January 1, 2021. The acquisition related costs associated with Onsite Energy included in other general and administrative expenses in the consolidated statements of comprehensive income were not material for the year ended January 1, 2021. During the fiscal 2020, the acquisition of Onsite Energy contributed $10.4 million in revenue and $0.3 million of income from operations. Acquisition of The Weidt Group ​ On March 8, 2019, the Company acquired substantially all of the assets of the energy practice division of The Weidt Group Inc. (“The Weidt Group”). The Company believes the acquisition will expand its presence in the upper Midwest and better position the Company to help utilities make their grids more resilient. Pursuant to the terms of the Asset Purchase Agreement, dated March 8, 2019, by and among the Company, WES and The Weidt Group, WES paid a cash purchase price of $22.1 million, inclusive of working capital adjustments. The Weidt Group’s financial information is included within the Energy segment. The Company finalized the purchase price allocation with respect to this transaction during the first quarter of 2020. The acquisition was accounted for as a business combination in accordance with ASC 805. Under ASC 805, the Company recorded the acquired assets and assumed liabilities at their estimated fair value with the excess allocated to goodwill. Goodwill represents the value the Company expects to achieve through the operational synergies, the expansion into new markets and the acquired company’s assembled work force. The Company estimates that the entire $11.5 million of goodwill resulting from the acquisition will be tax deductible. Consideration for the acquisition includes the following: ​ ​ ​ ​ ​ ​ The Weidt Group ​ ​ ​ (in thousands) Cash paid ​ $ 22,136 Other working capital adjustment ​ ​ - Total consideration ​ $ 22,136 ​ The following table summarizes the amounts for the acquired assets recorded at their estimated fair value as of the acquisition date: ​ ​ ​ ​ ​ ​ The Weidt Group ​ ​ ​ (in thousands) Current assets ​ $ 2,317 Non-current assets (1) ​ ​ 25 Equipment and leasehold improvements, net ​ ​ 198 Right-of-use assets ​ ​ 1,730 Current lease liability ​ ​ (245) Non-current lease liability ​ ​ (1,533) Liabilities ​ ​ (612) Backlog ​ ​ 750 Customer relationships ​ ​ 4,240 Tradename ​ ​ 550 Developed technology ​ ​ 3,170 Goodwill ​ ​ 11,546 Net assets acquired ​ $ 22,136 (1) Excluded from non-current assets are equipment and leasehold improvements, net, right-of-use assets, customer relationships, tradename, developed technology, backlog and goodwill. The acquisition related costs associated with The Weidt Group included in other general and administrative expenses in the consolidated statements of comprehensive income were not material for the year ended January 1, 2021. During the fiscal 2020, the acquisition of The Weidt Group contributed $14.9 million in revenue and $1.9 million of income from operations. The following unaudited pro forma financial information for the fiscal years ended January 1, 2021 and December 27, 2019 assumes that the acquisition of all of the capital stock of E3, Inc. and the acquisitions of substantially all of the assets and liabilities of Onsite Energy and The Weidt Group each occurred on the first day of the year prior to the year of acquisition: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fiscal Year ​ 2020 2019 ​ ​ (in thousands, except per share data) Pro forma revenue ​ $ 390,980 ​ $ 471,330 ​ ​ ​ ​ ​ ​ ​ Pro forma income (loss) from operations ​ $ (16,227) ​ $ 10,846 Pro forma net loss (1) ​ $ (14,496) ​ $ (16,618) ​ ​ ​ ​ ​ ​ ​ Loss per share: ​ ​ ​ ​ ​ ​ Basic ​ $ (1.23) ​ $ (1.49) Diluted ​ $ (1.23) ​ $ (1.41) ​ ​ ​ ​ ​ ​ ​ Weighted average shares outstanding: ​ ​ ​ ​ ​ ​ Basic ​ ​ 11,793 ​ ​ 11,162 Diluted ​ ​ 11,793 ​ ​ 11,766 (1) Adjustments to pro forma net income include income from operations, amortization and interest expenses. This pro forma supplemental information does not purport to be indicative of what the Company’s operating results would have been had the acquisition of all the capital stock of E3, Inc., and the acquisitions of substantially all of the assets and liabilities of Onsite Energy and The Weidt Group, each occurred on the first day of the year prior to the year of acquisition and may not be indicative of future operating results. During the fiscal year 2020, the acquisition of E3, Inc., Onsite Energy, and The Weidt Group contributed $48.4 million in revenue and $6.5 million of income from operations.

CONTINGENCIES

CONTINGENCIES	12 Months Ended
	Jan. 01, 2021
CONTINGENCIES
CONTINGENCIES	14. CONTINGENCIES Claims and Lawsuits The Company is subject to claims and lawsuits from time to time, including those alleging professional errors or omissions that arise in the ordinary course of business against firms that operate in the engineering and consulting professions. The Company carries professional liability insurance, subject to certain deductibles and policy limits, for such claims as they arise and may from time to time establish reserves for litigation that is considered probable of a loss. In accordance with accounting standards regarding loss contingencies, the Company accrues an undiscounted liability for those contingencies where the incurrence of a loss is probable and the amount can be reasonably estimated, and discloses the amount accrued and an estimate of any reasonably possible loss in excess of the amount accrued, if such disclosure is necessary for the Company’s financial statements not to be misleading. The Company does not accrue liabilities when the likelihood that the liability has been incurred is probable but the amount cannot be reasonably estimated, or when the liability is believed to be only reasonably possible or remote. Because litigation outcomes are inherently unpredictable, the Company’s evaluation of legal proceedings often involves a series of complex assessments by management about future events and can rely heavily on estimates and assumptions. If the assessments indicate that loss contingencies that could be material to any one of the Company’s financial statements are not probable, but are reasonably possible, or are probable, but cannot be estimated, then the Company will disclose the nature of the loss contingencies, together with an estimate of the possible loss or a statement that such loss is not reasonably estimable. While the consequences of certain unresolved proceedings are not presently determinable, and a reasonable estimate of the probable and reasonably possible loss or range of loss in excess of amounts accrued for such proceedings cannot be made, an adverse outcome from such proceedings could have a material adverse effect on the Company’s earnings in any given reporting period. However, in the opinion of the Company’s management, after consulting with legal counsel, and taking into account insurance coverage, the ultimate liability related to current outstanding claims and lawsuits is not expected to have a material adverse effect on the Company’s financial statements.

QUARTERLY FINANCIAL INFORMATION

QUARTERLY FINANCIAL INFORMATION (UNAUDITED)	12 Months Ended
	Jan. 01, 2021
QUARTERLY FINANCIAL INFORMATION (UNAUDITED)
QUARTERLY FINANCIAL INFORMATION (UNAUDITED)	15. QUARTERLY FINANCIAL INFORMATION (UNAUDITED) The tables below reflect selected quarterly information for the fiscal years ended January 1, 2021 and December 27, 2019. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fiscal Three Months Ended ​ ​ April 3, ​ July 3, ​ October 2, ​ January 1, ​ 2020 2020 2020 2021 ​ ​ (in thousands except per share amounts) Contract revenue ​ $ 106,026 ​ $ 83,549 ​ $ 104,508 ​ $ 96,897 ​ Income (loss) from operations ​ (8,269) ​ (3,841) ​ 1,601 ​ (5,718) ​ Income tax benefit ​ (1,605) ​ (90) ​ (1,586) ​ (1,892) ​ Net income (loss) ​ (8,154) ​ (4,985) ​ 2,640 ​ (3,997) ​ Earnings (loss) per share: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic ​ $ (0.71) ​ $ (0.43) ​ $ 0.22 ​ $ (0.33) ​ Diluted ​ $ (0.71) ​ $ (0.43) ​ $ 0.21 ​ $ (0.33) ​ Weighted-average shares outstanding: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic ​ 11,510 ​ 11,682 ​ 11,992 ​ 12,011 ​ Diluted ​ 11,510 ​ 11,682 ​ 12,417 ​ 12,011 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fiscal Three Months Ended ​ ​ March 29, ​ June 28, ​ September 27, ​ December 27, ​ 2019 2019 2019 2019 ​ ​ (in thousands except per share amounts ) Contract revenue ​ $ 91,793 ​ $ 104,396 ​ $ 117,494 ​ $ 129,416 ​ Income (loss) from operations ​ (234) ​ 2,773 ​ 1,295 ​ 5,529 ​ Income tax expense (benefit) ​ (927) ​ (70) ​ (376) ​ 1,188 ​ Net income (loss) ​ (417) ​ 1,640 ​ 416 ​ 3,202 ​ Earnings (loss) per share: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic ​ $ (0.04) ​ $ 0.15 ​ $ 0.04 ​ $ 0.28 ​ Diluted ​ $ (0.04) ​ $ 0.14 ​ $ 0.04 ​ $ 0.27 ​ Weighted-average shares outstanding: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic ​ 10,974 ​ 11,100 ​ 11,217 ​ 11,357 ​ Diluted ​ 10,974 ​ 11,679 ​ 11,789 ​ 11,913 ​ ​ ​

SUBSEQUENT EVENTS

SUBSEQUENT EVENTS	12 Months Ended
	Jan. 01, 2021
SUBSEQUENT EVENTS
SUBSEQUENT EVENTS	16. SUBSEQUENT EVENTS ​ The Company evaluates subsequent events in accordance with ASC Topic 855, Subsequent Events. The Company evaluates subsequent events up until the date the consolidated financial statements are issued. As of March 16, 2021, there were no subsequent events required to be reported.

ORGANIZATION AND OPERATIONS O_2

ORGANIZATION AND OPERATIONS OF THE COMPANY (Policies)	12 Months Ended
	Jan. 01, 2021
ORGANIZATION AND OPERATIONS OF THE COMPANY
Basis of Presentation	Basis of Presentation The Company has prepared its Consolidated Financial Statements in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”). The consolidated statement of stockholders' equity includes repurchases of shares of our common stock from employees to satisfy tax withholding obligations incurred in connection with the vesting of restricted stock or performance stock units, which amount is presented as a reduction of additional paid-in capital and common stock.
Fiscal Years	Fiscal Years The Company operates and reports its annual financial results based on 52 or 53-week periods ending on the Friday closest to December 31. The Company operates and reports its quarterly financial results based on the 13-week period ending on the Friday closest to June 30, September 30, and December 31 and the 13 or 14-week period ending on the Friday closest to March 31, as applicable. Fiscal year 2020, which ended on January 1, 2021, was comprised of 53 weeks, with the first quarter consisting of 14 weeks and the remaining quarters consisting of 13 weeks each. Fiscal year 2019, which ended on December 27, 2019, and fiscal year 2018, which ended on December 28, 2018, was comprised of 52 weeks, with all quarters presented consisting of 13 weeks. All references to years in the notes to consolidated financial statements represent fiscal years.
Principles of Consolidation	Principles of Consolidation The consolidated financial statements include the accounts of Willdan Group, Inc. and its wholly-owned subsidiaries and their respective subsidiaries. All significant intercompany balances and transactions have been eliminated in consolidation.
Reclassifications	Reclassifications Certain prior year amounts have been reclassified in the condensed consolidated balance sheets to conform to the current year presentation.
Use of Estimates	Use of Estimates The preparation of consolidated financial statements in conformity with generally accepted accounting principles in the U.S. requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements. Estimates also affect the reported amounts of revenue and expenses during the reporting period. Actual results could differ from those estimates.
Cash and Cash Equivalents	Cash and Cash Equivalents All highly liquid investments purchased with a remaining maturity of three months or less are considered to be cash equivalents. The Company from time to time may be exposed to credit risk with its bank deposits in excess of the FDIC insurance limits and with uninsured money market investments. The Company has not experienced any losses in such accounts and believes it is not exposed to any significant credit risk on cash and cash equivalents.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The Company uses the three-tier hierarchy of fair value measurement, which prioritizes the inputs. These tiers include: Level 1 (the highest priority), defined as observable inputs, such as quoted prices in active markets, Level 2, defined as inputs other than quoted prices in active markets that are either directly or indirectly observable; and Level 3 (the lowest priority), defined as unobservable inputs in which little or no market data exists, therefore requiring an entity to develop its own assumptions. ​ The Company’s financial instruments consist primarily of cash, cash equivalents, accounts receivable, contract assets, other receivables, prepaid expenses and other current assets, accounts payable, accrued liabilities and contract liabilities. The carrying amounts of certain other assets and contingent consideration are discounted to their present value because the time between the origination of these instruments and their expected realization or payment is greater than one year. ​ As of January 1, 2021 and December 27, 2019, the carrying amounts of the Company's cash and cash equivalents, accounts receivable, contract assets, other receivables, prepaid expenses and other current assets, accounts payable, accrued liabilities and contract liabilities, approximate their fair values because of the relatively short period of time between the origination of these instruments and their expected realization or payment. The carrying amounts of debt obligations approximate their fair values since the terms are comparable to terms currently offered by local lending institutions for loans of similar terms to companies with comparable credit risk. ​ The carrying amounts of the derivative financial instrument is valued based on Level 2 inputs. ​
Variable Interest Entities	Variable Interest Entities The Company accounts for variable interest entities in accordance with Accounting Standards Codification (“ASC”) 810, Consolidation. Under ASC 810, a variable interest entity (“VIE”) is created when any of the following criteria are present: (a) the equity investment at risk in the entity is not sufficient to permit the entity to finance its activities without additional subordinated financial support provided by other parties, including the equity holders; (b) the entity’s equity holders as a group either (i) lack the direct or indirect ability to make decisions about the entity, (ii) are not obligated to absorb expected losses of the entity or (iii) do not have the right to receive expected residual returns of the entity; or (c) the entity’s equity holders have voting rights that are not proportionate to their economic interests, and the activities of the entity involve or are conducted on behalf of the equity holder with disproportionately few voting rights. If an entity is deemed to be a VIE pursuant to ASC 810, the enterprise that has both (i) the power to direct the activities of a VIE that most significantly impact the entity’s economic performance and (ii) the obligation to absorb the expected losses of the entity or right to receive benefits from the entity that could be potentially significant to the VIE is considered the primary beneficiary and must consolidate the VIE. In accordance with ASC 810, the Company performs ongoing reassessments of whether an enterprise is the primary beneficiary of a VIE. As of January 1, 2021, the Company had one VIE — Genesys Engineering, P.C. (“Genesys”). Pursuant to New York law, the Company does not own capital stock of Genesys and does not have control over the professional decision making of Genesys’s engineering services. The Company, however, has entered into an administrative services agreement with Genesys pursuant to which WES, the Company’s wholly-owned subsidiary, will provide Genesys with ongoing administrative, operational and other non-professional support services. The Company manages Genesys and has the power to direct the activities that most significantly impact Genesys’s performance, in addition to being obligated to absorb expected losses from Genesys. Accordingly, the Company is the primary beneficiary of Genesys and consolidates Genesys as a VIE. Management also concluded there is no noncontrolling interest related to the consolidation of Genesys because management determined that (i) the shareholder of Genesys does not have more than a nominal amount of equity investment at risk, (ii) WES absorbs the expected losses of Genesys through its deferral of Genesys’s service fees owed to WES and the Company has, since entering into the administrative services agreement, had to continuously defer service fees for Genesys, and (iii) the Company believes Genesys will continue to have a shortfall on payment of its service fees for the foreseeable future, leaving no expected residual returns for the shareholder. For more information regarding Genesys, see Note 8 “Commitments and Variable Interest Entities.”
Segment Information	Segment Information The Company presents segment information externally consistent with the manner in which the Company’s chief operating decision maker reviews information to assess performance and allocate resources. The Company’s two segments are (i) Energy, and (ii) Engineering and Consulting. Willdan Group, Inc. (“WGI”) is a holding company and performs administrative functions on behalf of its subsidiaries, such as treasury, legal, accounting, information systems, human resources and certain business development activities, and earns revenue that is only incidental to the activities of the enterprise. As a result, WGI does not meet the definition of an operating segment.
Contract Assets and Liabilities	Contract Assets and Liabilities Billing practices are governed by the contract terms of each project based upon costs incurred, achievement of milestones or pre-agreed schedules. Billings do not necessarily correlate with revenue recognized using the percentage-of-completion method of revenue recognition. Contract assets include unbilled amounts typically resulting from revenue under contracts where the percentage-of-completion method of revenue recognition is utilized and revenue recognized exceeds the amount billed to the customer. In addition, contract assets include retainage amounts withheld from billings to the Company’s clients pursuant to provisions in our contracts. Contract liabilities consist of advance payments and billings in excess of revenue recognized and deferred revenue.
Adoption of ASC 606	Adoption of ASC 606 On December 30, 2017, the Company adopted ASC 606, using the modified retrospective method applied to those contracts which were not completed as of December 29, 2017. Prior to adopting ASC 606, the Company established an implementation team, which included senior managers from its finance and accounting group. The implementation team evaluated the impact of adopting ASC 606 on its contracts expected to be uncompleted as of December 30, 2017 (the date of adoption). The evaluation included reviewing its accounting policies and practices to identify differences that would result from applying the requirements of the new standard. The Company identified and made changes to its processes, systems and controls to support recognition and disclosure under the new standard. The implementation team worked closely with various professional consultants and attended several formal conferences and seminars to conclude on certain interpretative issues. The Company recognizes engineering and consulting contract revenue over time using the percentage-of-completion method, based primarily on contract cost incurred to date compared to total estimated contract cost. Revenue on the vast majority of its contracts will continue to be recognized over time because of the continuous transfer of control to the customer. Revenue recognition for software licenses issued by the Energy segment is recognized at a point in time, upon acceptance of the software by the customer and in recognition of the fulfillment of the performance obligation. Certain additional performance obligations beyond the base software license may be separated from the gross license fee and recognized on a straight-line basis over time.
Contract Accounting	Contract Accounting The Company enters into contracts with its clients that contain various types of pricing provisions, including fixed price, time-and-materials, and unit-based provisions. The Company recognizes revenues in accordance with ASU 2014-09, Revenue from Contracts with Customer, codified as ASC Topic 606 and the related amendments (collectively “ASC 606”). As such, the Company identifies a contract with a customer, identifies the performance obligations in the contract, determines the transaction price, allocates the transaction price to each performance obligation in the contract and recognizes revenues when (or as) the Company satisfies a performance obligation. The following table reflects the Company’s two reportable segments and the types of contracts that each most commonly enters into for revenue generating activities. ​ Segment Contract Type Revenue Recognition Method ​ Time-and-materials Time-and-materials Energy Unit-based Unit-based ​ Software license Unit-based ​ Fixed price Percentage-of-completion ​ Time-and-materials Time-and-materials Engineering and Consulting Unit-based Unit-based ​ Fixed price Percentage-of-completion ​ Revenue on the vast majority of the Company’s contracts will continue to be recognized over time because of the continuous transfer of control to the customer. Revenue on fixed price contracts is recognized on the percentage-of-completion method based generally on the ratio of direct costs incurred-to-date to estimated total direct costs at completion. The Company uses the percentage-of-completion method to better match the level of work performed at a certain point in time in relation to the effort that will be required to complete a project. In addition, the percentage-of-completion method is a common method of revenue recognition in the Company’s industry. Many of the Company’s fixed price contracts involve a high degree of subcontracted fixed price effort and are relatively short in duration, thereby lowering the risks of not properly estimating the percent complete. Revenue on time-and-materials and unit-based contracts is recognized as the work is performed in accordance with the specific rates and terms of the contract. The Company recognizes revenues for time-and-materials contracts based upon the actual hours incurred during a reporting period at contractually agreed upon rates per hour and also includes in revenue all reimbursable costs incurred during a reporting period. Certain of the Company’s time-and-materials contracts are subject to maximum contract values and, accordingly, when revenue is expected to exceed the maximum contract value, these contracts are generally recognized under the percentage-of-completion method, consistent with fixed price contracts. For unit-based contracts, the Company recognizes the contract price of units of a basic production product as revenue when the production product is delivered during a period. Revenue recognition for software licenses issued by the Energy segment is generally recognized at a point in time, utilizing the unit-based revenue recognition method, upon acceptance of the software by the customer and in recognition of the fulfillment of the performance obligation. Certain additional performance obligations beyond the base software license may be separated from the gross license fee and recognized on a straight-line basis over time. Revenue for amounts that have been billed but not earned is deferred, and such deferred revenue is referred to as contract liabilities in the accompanying condensed consolidated balance sheets. To determine the proper revenue recognition method for contracts, the Company evaluates whether two or more contracts should be combined and accounted for as one single contract and whether the combined contract should be accounted for as one performance obligation. With respect to the Company’s contracts, it is rare that multiple contracts should be combined into a single performance obligation. This evaluation requires significant judgment and the decision to combine a group of contracts or separate a single contract into multiple performance obligations could change the amount of revenue and profit recorded in a given period. Contracts are considered to have a single performance obligation if the promise to transfer the individual goods or services is not separately identifiable from other promises in the contracts, which is mainly because the Company provides a significant service of integrating a complex set of tasks and components into a single project or capability. The Company may enter into contracts that include separate phases or elements. If each phase or element is negotiated separately based on the technical resources required and/or the supply and demand for the services being provided, the Company evaluates if the contracts should be segmented. If certain criteria are met, the contracts would be segmented which could result in revenues being assigned to the different elements or phases with different rates of profitability based on the relative value of each element or phase to the estimated total contract revenue. Segmented contracts may comprise up to approximately 2.0% to 3.0% of the Company’s consolidated contract revenue. Contracts that cover multiple phases or elements of the project or service lifecycle (development, construction and maintenance and support) may be considered to have multiple performance obligations even when they are part of a single contract. For contracts with multiple performance obligations, the Company allocates the transaction price to each performance obligation using the best estimate of the standalone selling price of each distinct good or service in the contract. For the periods presented, the value of the separate performance obligations under contracts with multiple performance obligations (generally measurement and verification tasks under certain energy performance contracts) were not material. In cases where the Company does not provide the distinct good or service on a standalone basis, the primary method used to estimate standalone selling price is the expected cost plus a margin approach, under which the Company forecasts the Company’s expected costs of satisfying a performance obligation and then adds an appropriate margin for the distinct good or service. The Company provides quality of workmanship warranties to customers that are included in the sale and are not priced or sold separately or do not provide customers with a service in addition to assurance of compliance with agreed-upon specifications and industry standards. The Company does not consider these types of warranties to be separate performance obligations. In some cases, the Company has a master service or blanket agreement with a customer under which each task order releases the Company to perform specific portions of the overall scope in the service contract. Each task order is typically accounted for as a separate contract because the task order establishes the enforceable rights and obligations, and payment terms. Under ASC 606, variable consideration should be considered when determining the transaction price and estimates should be made for the variable consideration component of the transaction price, as well as assessing whether an estimate of variable consideration is constrained. For certain of the Company’s contracts, variable consideration can arise from modifications to the scope of services resulting from unapproved change orders or customer claims. Variable consideration is included in the transaction price to the extent it is probable that a significant reversal of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is resolved. The Company estimates of variable consideration and determination of whether to include estimated amounts in the transaction price are based largely on assessments of legal enforceability, the Company’s performance, and all information (historical, current and forecasted) that is reasonably available to the Company. Due to the nature of the work required to be performed on many of the Company’s performance obligations, the estimation of total revenue and cost at completion is complex, subject to many variables and requires significant judgment. As a significant change in one or more of these estimates could affect the profitability of the Company’s contracts, the Company reviews and updates the Company’s contract-related estimates regularly through a company-wide disciplined project review process in which management reviews the progress and execution of the Company’s performance obligations and the estimate at completion (EAC). As part of this process, management reviews information including, but not limited to, any outstanding key contract matters, progress towards completion and the related program schedule and the related changes in estimates of revenues and costs. Management must make assumptions and estimates regarding labor productivity and availability, the complexity of the work to be performed, the cost and availability of materials, the performance of subcontractors, and the availability and timing of funding from the customer, among other variables. The Company recognizes adjustments in estimated profit on contracts under the cumulative catch-up method. Under this method, the impact of the adjustment on profit recorded to date is recognized in the period the adjustment is identified. Revenue and profit in future periods of contract performance is recognized using the adjusted estimate. If at any time the estimate of contract profitability indicates an anticipated loss on the contract, the Company recognizes the full amount of estimated loss in the period it is identified. Contracts are often modified to account for changes in contract specifications and requirements. The Company considers contract modifications to exist when the modification either creates new rights or obligations or changes the existing enforceable rights or obligations. Most of the Company’s contract modifications are for goods or services that are not distinct from existing contracts due to the significant integration provided in the context of the contract and are accounted for as if they were part of the original contract. The effect of a contract modification that is not distinct from the existing contract on the transaction price and the Company’s measure of progress for the performance obligation to which it relates is recognized as an adjustment to revenue (either as an increase in or a reduction of revenue) on a cumulative catch-up basis. For contract modifications that result in the promise to deliver goods or services that are distinct from the existing contract and the increase in price of the contract is for the same amount as the standalone selling price of the additional goods or services included in the modification, the Company accounts for such contract modifications as a separate contract. The Company includes claims to vendors, subcontractors and others as a receivable and a reduction in recognized costs when enforceability of the claim is established by the contract and the amounts are reasonably estimable and probable of being recovered. The amounts are recorded up to the extent of the lesser of the amounts management expects to recover or to costs incurred. Billing practices are governed by the contract terms of each project based upon costs incurred, achievement of milestones or pre-agreed schedules. Billings do not necessarily correlate with revenue recognized using the percentage-of-completion method of revenue recognition. Direct costs of contract revenue consist primarily of that portion of technical and nontechnical salaries and wages that has been incurred in connection with revenue producing projects. Direct costs of contract revenue also include production expenses, subcontractor services and other expenses that are incurred in connection with revenue producing projects. Direct costs of contract revenue exclude that portion of technical and nontechnical salaries and wages related to marketing efforts, vacations, holidays and other time not spent directly generating revenue under existing contracts. Such costs are included in general and administrative expenses. Additionally, payroll taxes, bonuses and employee benefit costs for all Company personnel are included in general and administrative expenses in the accompanying consolidated statements of comprehensive income since no allocation of these costs is made to direct costs of contract revenue. No allocation of facilities costs is made to direct costs of contract revenue. Other companies may classify as direct costs of contract revenue some of the costs that the Company classifies as general and administrative costs. The Company expenses direct costs of contract revenue when incurred. Included in revenue and costs are all reimbursable costs for which the Company has the risk or on which the fee was based at the time of bid or negotiation. No revenue or cost is recorded for costs in which the Company acts solely in the capacity of an agent and has no risks associated with such costs. Accounts receivable are carried at original invoice amount less an estimate made for doubtful accounts based upon a review of all outstanding amounts on a quarterly basis. Management determines allowances for doubtful accounts through specific identification of amounts considered to be uncollectible and potential write-offs, plus a non-specific allowance for other amounts for which some potential loss has been determined to be probable based on current and past experience. The Company’s historical credit losses have been minimal with governmental entities and large public utilities, but disputes may arise related to these receivable amounts. Accounts receivable are written off when deemed uncollectible. Recoveries of accounts receivable previously written off are recorded when received. Retainage, included in contract assets, represents amounts withheld from billings to the Company’s clients pursuant to provisions in the contracts and may not be paid to the Company until specific tasks are completed or the project is completed and, in some instances, for even longer periods. At January 1, 2021 and December 27, 2019, contract assets included retainage of approximately $6.2 million and $5.4 million, respectively. In addition to the above, the Company derives revenue from software licenses and professional services and maintenance fees. In accordance with ASC 606, the Company performs an assessment of each contract to identify the performance obligations, determine the overall transaction price for the contract, allocate the transaction price to the performance obligations, and recognize the revenue when the performance obligations are satisfied. The Company utilizes the residual approach by which it estimates the standalone selling price by reference to the total transaction price less the sum of the observable standalone selling prices of other goods or services promised in the contract. The software license revenue is typically recognized at a point in time when control is transferred to the client, which is defined as the point in time when the client can use and benefit from the license. The software license is delivered before related services are provided and is functional without services, updates, or technical support. Related professional services include training and support services in which the standalone selling price is determined based on an input measure of hours incurred to total estimated hours and is recognized over time, usually which is the life of the contract.
General and Administrative Expenses	General and Administrative Expenses General and administrative expenses include the costs of the marketing and support staff, other marketing expenses, management and administrative personnel costs, payroll taxes, bonuses and employee benefits for all of the Company’s employees and the portion of salaries and wages not allocated to direct costs of contract revenue for those employees who provide the Company’s services. General and administrative expenses also include facility costs, depreciation and amortization, professional services, legal and accounting fees and administrative operating costs. Within general and administrative expenses, “Other” includes expenses such as provision for billed or unbilled receivables, professional services, legal and accounting, computer costs, travel and entertainment, marketing costs and acquisition costs. The Company expenses general and administrative costs when incurred.
Leases	Leases In February 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2016-02, Leases (Topic 842) (“ASU 2016-02”). ASU 2016-02 require, among other things, that lessees recognize the following for all leases (unless a policy election is made by class of underlying asset to exclude short-term leases) at the commencement date: (1) a lease liability, which is a lessee’s obligation to make lease payments arising from a lease, measured on a discounted basis; and (2) a right-of-use asset, which is an asset that represents the lessee’s right to use, or the direct use of, a specified asset for the lease term. The FASB issued ASU 2018-11 on July 30, 2018, which allows entities to apply the provisions of ASC 842 at the effective date without adjusting comparative periods. ​ On December 29, 2018, the Company adopted ASU 2016-02 using the modified retrospective method. Under this guidance, the net present value of future lease payments is recorded as right-of-use assets and lease liabilities. In addition, the Company elected the ‘package of practical expedients’ permitted under the transition guidance within the new standard, which among other things, allowed the Company to carry forward the historical lease classification. In addition, the Company elected not to utilize the hindsight practical expedient to determine the lease term for existing leases. The Company also elected the practical expedient to not separate lease and non-lease components for its facilities leases. Previously, all of the Company’s office leases were classified as operating leases and rent expense was included in facilities expense in the consolidated statements of comprehensive income. ​ In addition, the Company leases certain equipment under financing leases. The economic substance of the leases is a financing transaction for acquisition of equipment and leasehold improvements. Accordingly, the right-of-use assets for these leases are included in the balance sheets in equipment and leasehold improvements, net of accumulated depreciation, with a corresponding amount recorded in current portion of financing lease obligations or noncurrent portion of financing lease obligations, as appropriate. The financing lease assets are amortized over the life of the lease or, if shorter, the life of the leased asset, on a straight-line basis and included in depreciation expense in the statements of comprehensive income. The interest associated with financing lease obligations is included in interest expense in the statements of comprehensive income. For more information, see Note 2, “ Recent Accounting Pronouncements Leases
Equipment and Leasehold Improvements	Equipment and Leasehold Improvements Equipment and leasehold improvements are stated at cost less accumulated depreciation and amortization. Equipment under capital leases is stated at the present value of the minimum lease payments as of the acquisition date. Depreciation and amortization on equipment are calculated using the straight-line method over estimated useful lives of two Following are the estimated useful lives used to calculate depreciation and amortization: ​ ​ ​ ​ ​ Category Estimated Useful Life Furniture and fixtures 5 years Computer hardware 3 years Computer software 3 years Automobiles and trucks 3 years Field equipment 5 years
Goodwill	Goodwill Goodwill represents the excess of costs over fair value of the assets acquired. The Company completes its annual testing of goodwill as of the last day of the first month of its fourth fiscal quarter each year to determine whether there is impairment. Goodwill, which has an indefinite useful life, is not amortized, but instead tested for impairment at least annually or more frequently if events and circumstances indicate that the asset might be impaired. Impairment losses for reporting units are recognized to the extent that a reporting unit’s carrying amount exceeds its fair value.
Long-lived assets	Long-lived assets Long-lived assets, such as equipment, leasehold improvements and purchased intangible assets subject to amortization are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to estimated undiscounted future cash flows expected to be generated by the asset. If the carrying amount of an asset exceeds its estimated future cash flows, an impairment charge is recognized by the amount by which the carrying amount of the asset exceeds the fair value of the asset.
Accounting for Claims against the Company	Accounting for Claims against the Company The Company accrues an undiscounted liability related to claims against it for which the incurrence of a loss is probable and the amount can be reasonably estimated. The Company discloses the amount accrued and an estimate of any reasonably possible loss in excess of the amount accrued, if such disclosure is necessary for its financial statements not to be misleading. The Company does not accrue liabilities related to claims when the likelihood that a loss has been incurred is probable but the amount cannot be reasonably estimated, or when the liability is believed to be only reasonably possible or remote. Losses related to recorded claims are included in general and administrative expenses. Determining probability and estimating claim amounts is highly judgmental. Initial accruals and any subsequent changes in the Company’s estimates could have a material effect on its consolidated financial statements.
Stock-based Compensation	Stock-based Compensation The Company accounts for all stock-based compensation under the fair value recognition provisions of the accounting standard entitled “ Compensation—Stock Compensation.
Business Combinations	Business Combinations The acquisition method of accounting for business combinations requires the Company to use significant estimates and assumptions, including fair value estimates, as of the business combination date and to refine those estimates as necessary during the measurement period (defined as the period, not to exceed one year, in which the Company may adjust the provisional amounts recognized for a business combination based upon new information about facts that existed on the business combination date). Under the acquisition method of accounting, the Company recognizes separately from goodwill the identifiable assets acquired, the liabilities assumed, and any non-controlling interests in an acquiree, at the acquisition date fair value. The Company measures goodwill as of the acquisition date as the excess of consideration transferred over the net of the acquisition date amounts of the identifiable assets acquired and liabilities assumed. Costs that the Company incurs to complete the business combination such as investment banking, legal and other professional fees are not considered part of consideration. The Company charges these acquisition costs to general and administrative expense as they are incurred. On October 28, 2019, the Company acquired all of the capital stock of Energy and Environmental Economics, Inc. (“E3, Inc.”). On July 2, 2019, the Company acquired substantially all of the assets and liabilities of Onsite Energy Corporation (“Onsite Energy”). On March 8, 2019, the Company acquired substantially all of the assets of the energy practice division of The Weidt Group Inc. (“The Weidt Group”). For further discussion of these acquisitions, see Note 13 “ Business Combinations
Income Taxes	Income Taxes Income taxes are accounted for under the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences of temporary differences between the financial reporting basis and tax basis of the Company’s assets and liabilities, subject to a judgmental assessment of the recoverability of deferred tax assets. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. A valuation allowance is recorded when it is more-likely-than-not that some of the deferred tax assets may not be realized. Significant judgment is applied when assessing the need for valuation allowances. Areas of estimation include the Company’s consideration of future taxable income and ongoing prudent and feasible tax planning strategies. Should a change in circumstances lead to a change in judgment about the utilization of deferred tax assets in future years, the Company would adjust the related valuation allowances in the period that the change in circumstances occurs, along with a corresponding increase or charge to income. During each fiscal year, management assesses the available positive and negative evidence to estimate if sufficient future taxable income will be generated to utilize existing deferred tax assets. For fiscal years 2020 and 2019, the Company ultimately determined that it was more-likely-than-not that the entire California net operating loss will not be utilized prior to expiration. Significant pieces of objective evidence evaluated included the Company’s history of utilization of California net operating losses in prior years for each of the Company’s subsidiaries, as well as the Company’s forecasted amount of net operating loss utilization for certain members of the combined group. As a result, at the end of fiscal years 2020 and 2019, the Company recorded a valuation allowance in the amount of $86,000, for each year, related to California net operating losses. For acquired business entities, if the Company identifies changes to acquired deferred tax asset valuation allowances or liabilities related to uncertain tax positions during the measurement period and they relate to new information obtained about facts and circumstances that existed as of the acquisition date, those changes are considered a measurement period adjustment and the Company records the offset to goodwill. The Company records all other changes to deferred tax asset valuation allowances and liabilities related to uncertain tax positions in current period income tax expense. The Company recognizes the tax benefit from uncertain tax positions if it is more likely than not that the tax positions will be sustained on examination by the tax authorities, based on the technical merits of the position. The tax benefit is measured based on the largest benefit that has a greater than 50% likelihood of being realized upon ultimate settlement. The Company recognizes interest and penalties related to unrecognized tax benefits in income tax expense.
Earnings per Share	Earnings per Share ​ The Company computes basic income per common share using net income and the weighted average number of common shares outstanding during the period. Diluted income per common share is computed using net income and the weighted average number of common shares and potentially dilutive common shares outstanding during the period. Potentially dilutive common shares include dilutive outstanding employee stock options, RSAs, PBRSUs, and rights to purchase shares of common stock under the Company’s ESPP.
Other Comprehensive Income (loss), Net of Tax	Other Comprehensive Income (loss), Net of Tax ​ Other comprehensive income (loss), net of tax refers to revenue, expenses, gains and losses that are recorded as an element of shareholders’ equity but are excluded from net income. The Company’s other comprehensive income (loss), net of tax is comprised of unrealized gains or losses on its interest rate swap agreement designated as cash flow hedges.
Derivatives	Derivatives The Company accounts for its interest rate swap as designated cash flow hedges to mitigate variations in interest payments under a portion of its LIBOR-based term loans due to variations in the LIBOR index. The Company pays interest monthly at a fixed rate and receives interest monthly at the LIBOR rate on the notional amount of the contract with realized gains or losses recognized in interest expense.
Operating Cycle	Operating Cycle In accordance with industry practice, amounts realizable and payable under contracts that extend beyond one year are included in current assets (included in contract assets) and current liabilities.
Management's Plans in Response to Covid-19	Management’s Plans in Response to Covid-19 On January 30, 2020, the spread of a novel strain of coronavirus (“Covid-19”) was declared a Public Health Emergency of International Concern by the World Health Organization (“WHO”). On March 11, 2020, WHO characterized the Covid-19 outbreak as a pandemic. The Covid-19 pandemic has resulted in governmental authorities around the world implementing numerous measures to try to contain the virus, such as travel bans and restrictions, quarantines, shelter-in-place or total lock-down orders and business limitations and shutdowns (subject to exceptions for certain essential operations and businesses). Although some of these measures have since been lifted or scaled back, ongoing resurgences of Covid-19 in the United States has resulted in the reimposition of certain restrictions and may lead to other restrictions being reimplemented in response to efforts to reduce the spread of Covid-19. The Covid-19 outbreak and restrictions intended to slow the spread of Covid-19 have caused economic and social disruption on an unprecedented scale. It is unclear how long these restrictions will remain in place and they may remain in place in some form for an extended period of time. Given the uncertainties associated with the duration of the pandemic, the Company cannot reasonably estimate the ultimate impacts of Covid-19 and efforts to limit its spread on its business, financial condition, results of operations or cash flows for the foreseeable future or whether the Company’s assumptions used to estimate its future liquidity requirements will be correct . ​ Health and Safety ​ Financial Position and Results of Operations ​ In the Energy segment, the Company has experienced, and expects to continue to experience, a negative impact on its direct install programs that serve small businesses as a result of restrictions put in place by governmental authorities that have required temporary shutdowns of all “non-essential” businesses. In fiscal year 2019, the Company derived approximately 40% of its gross revenue from its direct install programs that serve small businesses, and a significant portion of the Company’s direct install work on these programs was suspended for varying periods of time during fiscal year 2020. With the exception of the direct install programs in California, phased re-openings have continued to progress since the second quarter of 2020. The Company’s other programs, which generated approximately 60% of our revenue in fiscal 2019, are either businesses that have been determined to be “essential” by government authorities or have continued to progress during the pandemic. ​ In the Engineering and Consulting segment, the Company’s revenues have been less affected by Covid-19 than the revenues in the Energy Segment. The services in this segment have generally been deemed “essential” by the government and have continued to operate while abiding social distancing measures. ​ As of March 15, 2021, though some of the Company’s work has been suspended as a result of the Covid-19 pandemic and efforts to limit its spread, none of its contracts have been cancelled and proposal activities for new programs have continued to advance. The Company estimates that pandemic related slowdowns and work suspensions reduced the fiscal 2020 revenue by approximately 20% from its planned pre-pandemic levels for 2020. ​ ​ ● Executing a reduction in workforce, primarily through an unpaid furlough, impacting approximately 300 members of the Company’s staff. The largest reductions were a result of government-mandated work restrictions impacting the Company’s direct install programs in California and New York. During the Company’s second fiscal quarter, furloughed employees began to return to work as government authorities began lifting restrictions through phased re-openings and, by the end of the third fiscal quarter, the majority of the Company’s furloughed employees had returned to work ; ​ ● A temporary freeze on all non-critical spending for travel, capital expenditures, and other discretionary expenses; ​ ● A temporary cash wage reduction for salaried employees, ranging from 0% for lower salary bands up to 75% for senior management, all of which had been restored by the end of July 2020; ​ ● Suspension of cash fees for the Company’s Board of Directors, which was lifted during the third fiscal quarter; ​ ● Implementing a temporary hiring freeze; and ​ ● Amending the Company’s credit facility for increased flexibility. ​ The Company believes that its financial position is sufficiently flexible to enable it to maneuver in the current economic environment. Throughout the fiscal year 2020, the Company enhanced liquidity by minimizing working capital and significantly improving cash collections. In addition, in May 2020, the Company amended its credit facility to temporarily modify, among other things, certain covenants to increase its financial flexibility. Combined with availability under its credit facilities, the Company believes its enhanced liquidity position provides a cushion against liquidity disruptions. ​ Asset and liability valuation and other estimates used in preparation of financial statements ​ Changes to the estimated future profitability of the business may require that the Company establish an additional valuation allowance against all or some portion of its net deferred tax assets. Impact on Clients and Subcontractors and Other Risks The Company primarily work for utilities, municipalities and other public agencies. The Company expects many governmental and other public agencies could have significant budget shortfalls for 2020 and potentially beyond as a result of the economic slowdown from the measures taken to mitigate the Covid-19 pandemic. Although none of the Company’s contracts with governmental or other public agencies were materially modified during fiscal year 2020, these potential budget deficits could result in delayed funding for existing contracts with the Company, postponements of new contracts or price concessions. Further, most of the Company’s clients are not committed to purchase any minimum amount of the Company’s services, as the Company’s agreements with them are based on a “purchase order” model. As a result, they may discontinue utilizing some or all of the Company’s services with little or no notice. In addition, the Company relies on subcontractors and material suppliers to complete a substantial portion of the work, especially in the Company’s Energy segment. If the Company’s significant subcontractors and material suppliers suffer significant economic harm and must limit or cease operations or file for bankruptcy as a result of the current economic slowdown, the Company’s subcontractors and material suppliers may not be able to fulfill their contractual obligations satisfactorily and the Company may not have the ability to select its subcontractors and material suppliers of choice for new contracts. If the Company’s subcontractors and material suppliers are not able to fulfill their contractual obligations, it could result in a significant increase in costs for the Company to complete the projects or cause significant delays to the realization of revenues under those projects. The ultimate impact of Covid-19 on the Company’s financial condition and results of operations will depend on all of the factors noted above, including other factors that the Company may not be able to forecast at this time. See the risk factor “ The Covid-19 pandemic and health and safety measures intended to slow its spread have adversely affected, and may continue to adversely affect, our business, results of operations and financial condition.” Risk Factors

ORGANIZATION AND OPERATIONS O_3

ORGANIZATION AND OPERATIONS OF THE COMPANY (Tables)	12 Months Ended
	Jan. 01, 2021
ORGANIZATION AND OPERATIONS OF THE COMPANY
Schedule of contracts by reportable segments and type of contracts	​ Segment Contract Type Revenue Recognition Method ​ Time-and-materials Time-and-materials Energy Unit-based Unit-based ​ Software license Unit-based ​ Fixed price Percentage-of-completion ​ Time-and-materials Time-and-materials Engineering and Consulting Unit-based Unit-based ​ Fixed price Percentage-of-completion
Schedule of the estimated useful lives used to calculate depreciation and amortization	​ ​ ​ ​ ​ Category Estimated Useful Life Furniture and fixtures 5 years Computer hardware 3 years Computer software 3 years Automobiles and trucks 3 years Field equipment 5 years

SUPPLEMENTAL FINANCIAL STATEM_2

SUPPLEMENTAL FINANCIAL STATEMENT DATA (Tables)	12 Months Ended
	Jan. 01, 2021
SUPPLEMENTAL FINANCIAL STATEMENT DATA
Schedule of accounts receivable	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ January 1, ​ December 27, ​ 2021 2019 ​ ​ (in thousands) Billed ​ $ 62,530 ​ $ 58,651 Unbilled (1) ​ ​ 56,262 ​ ​ 96,041 Contract retentions ​ ​ 6,164 ​ ​ 5,377 Other assets (2) ​ ​ 4,524 ​ ​ 14,075 ​ ​ ​ 129,480 ​ ​ 174,144 Allowance for doubtful accounts ​ ​ (2,127) ​ ​ (1,147) ​ ​ $ 127,353 ​ $ 172,997 ​ (1) Unbilled portion represents contract assets which is presented separately from accounts receivable on the consolidated balance sheets. (2) Other assets represents a portion of receivables greater than one year from the normal course of business presented separately from current assets on the consolidated balance sheets. ​
Schedule of the movements in the allowance for doubtful accounts	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fiscal Year ​ 2020 2019 2018 ​ ​ (in thousands) Balance as of the beginning of the year ​ $ 1,147 ​ $ 442 ​ $ 369 (Recovery of) provision for doubtful accounts ​ 1,329 ​ 1,051 ​ 470 Write-offs of uncollectible accounts ​ (388) ​ (346) ​ (397) Fair value adjustment ​ 39 ​ — ​ — Balance as of the end of the year ​ $ 2,127 ​ $ 1,147 ​ $ 442
Schedule of equipment and leasehold improvements	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ January 1, ​ December 27, ​ ​ 2021 2019 ​ ​ (in thousands) Furniture and fixtures ​ $ 4,088 ​ $ 4,614 Computer hardware and software ​ 18,047 ​ 14,789 Leasehold improvements ​ 2,994 ​ 2,410 Equipment under finance leases ​ 2,370 ​ 1,957 Automobiles, trucks, and field equipment ​ 3,216 ​ 3,564 Subtotal ​ 30,715 ​ 27,334 Accumulated depreciation and amortization ​ (18,209) ​ (15,283) Equipment and leasehold improvements, net ​ $ 12,506 ​ $ 12,051
Schedule of accrued liabilities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ January 1, ​ December 27, ​ 2021 2019 ​ ​ (in thousands) Accrued subcontractor costs ​ $ 19,124 ​ $ 45,366 Other ​ 11,981 ​ 4,630 Accrued bonuses ​ ​ 5,211 ​ ​ 7,756 Employee withholdings ​ 2,768 ​ 3,463 Compensation and payroll taxes ​ 1,983 ​ 3,286 Paid leave bank ​ 687 ​ 3,114 Total accrued liabilities ​ $ 41,754 ​ $ 67,615
Schedule of changes in the carrying value of goodwill by reporting unit	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 27, ​ Additional ​ Additions / ​ January 1, ​ 2019 Purchase Cost Adjustments 2021 ​ ​ (in thousands) Reporting Unit: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Energy ​ $ 126,898 ​ $ — ​ $ 2,477 ​ $ 129,375 Engineering and Consulting ​ ​ 749 ​ ​ — ​ ​ — ​ ​ 749 ​ ​ $ 127,647 ​ $ — ​ $ 2,477 ​ $ 130,124 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 28, ​ Additional ​ Additions / ​ December 27, ​ 2018 Purchase Cost Adjustments 2019 ​ ​ (in thousands) Reporting Unit: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Energy ​ $ 96,999 ​ $ 39,690 ​ $ (9,791) ​ $ 126,898 Engineering and Consulting ​ ​ 749 ​ ​ ​ ​ ​ ​ ​ ​ 749 ​ ​ $ 97,748 ​ $ 39,690 ​ $ (9,791) ​ $ 127,647
Schedule of gross amounts and accumulated amortization of the Company's acquired identifiable intangible assets with finite useful lives	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ January 1, 2021 ​ December 27, 2019 ​ ​ ​ ​ ​ ​ ​ ​ Gross ​ Accumulated ​ Gross ​ Accumulated ​ Amortization ​ Amount Amortization Amount Amortization Period ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (in years) Finite: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Backlog ​ $ 7,944 ​ $ 6,249 ​ $ 7,134 ​ $ 3,763 ​ 1.0 Tradename ​ 15,911 ​ 6,984 ​ 13,351 ​ 4,882 2.5 ​ - ​ 6.0 Non-compete agreements ​ ​ 1,420 ​ ​ 1,390 ​ ​ 2,320 ​ ​ 1,384 ​ 4.0 ​ - ​ 5.0 Developed technology ​ ​ 15,500 ​ ​ 6,107 ​ ​ 14,620 ​ ​ 3,227 ​ 8.0 Customer relationships ​ 58,149 ​ ​ 14,248 ​ ​ 60,733 ​ ​ 8,065 5.0 ​ - ​ 8.0 Total finite intangible assets ​ $ 98,924 ​ $ 34,978 ​ $ 98,158 ​ $ 21,321 ​ ​ ​ ​ ​ ​ In-process research and technology (1) ​ ​ 310 ​ ​ — ​ ​ — ​ ​ — ​ ​ ​ ​ ​ ​ Total intangible assets ​ $ 99,234 ​ $ 34,978 ​ $ 98,158 ​ $ 21,321 ​ ​ ​ ​ ​ ​ ​ (1) In-process research and technology is not amortized until put into use.

DERIVATIVE FINANCIAL INSTRUME_2

DERIVATIVE FINANCIAL INSTRUMENTS (Tables)	12 Months Ended
	Jan. 01, 2021
DERIVATIVE FINANCIAL INSTRUMENTS
Schedule of fair values of outstanding derivatives designated as hedging instruments	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value of Derivative ​ ​ Instruments as of ​ ​ Balance Sheet Location ​ January 1, 2021 ​ December 27, 2019 ​ ​ ​ ​ (in thousands) Interest rate swap agreement ​ Accrued liabilities ​ $ (624) ​ $ (241) Interest rate swap agreement ​ Other noncurrent (liabilities) assets ​ $ (48) ​ $ (306)
Schedule of accumulated other comprehensive income (loss)	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gain (Loss) on ​ Accumulated Other ​ Derivative Instruments Comprehensive Loss ​ ​ (in thousands) Balances at December 28, 2018 ​ $ — ​ $ — Other comprehensive loss before reclassifications ​ ​ (546) ​ ​ (546) Amounts reclassified from accumulated other comprehensive income: ​ ​ ​ ​ ​ ​ Income tax benefit (expense) related to derivative instruments ​ ​ 150 ​ ​ 150 Net current-period other comprehensive loss ​ ​ (396) ​ ​ (396) Balances at December 27, 2019 ​ $ (396) ​ $ (396) Other comprehensive loss before reclassifications ​ ​ (126) ​ ​ (126) Amounts reclassified from accumulated other comprehensive income: ​ ​ ​ ​ ​ ​ Income tax benefit (expense) related to derivative instruments ​ ​ 34 ​ ​ 34 Net current-period other comprehensive loss ​ ​ (488) ​ ​ (488) Balances at January 1, 2021 ​ $ (488) ​ $ (488)

DEBT OBLIGATIONS (Tables)

DEBT OBLIGATIONS (Tables)	12 Months Ended
	Jan. 01, 2021
DEBT OBLIGATIONS
Schedule of debt obligations, excluding obligations under capital leases	​ ​ ​ ​ ​ ​ ​ ​ ​ January 1, December 27, ​ ​ 2021 ​ 2019 ​ ​ (in thousands) Outstanding borrowings on Term A Loan ​ $ 85,000 ​ $ 95,000 Outstanding borrowings on Revolving Credit Facility ​ ​ — ​ ​ 5,000 Outstanding borrowings on Delayed Draw Term Loan ​ ​ 27,000 ​ ​ 30,000 Other debt agreements ​ ​ 1,996 ​ ​ 1,060 Total debt ​ ​ 113,996 ​ ​ 131,060 Issuance costs and debt discounts ​ ​ (822) ​ ​ (709) Subtotal ​ ​ 113,174 ​ ​ 130,351 Less current portion of long-term debt ​ 14,996 ​ 13,720 Long-term debt portion ​ $ 98,178 ​ $ 116,631
Schedule of principal installments for the Company's debt obligations excluding capital leases	The following table summarizes the combined principal installments for the Company’s debt obligations, excluding capital leases, over the next five years and beyond, as of January 1, 2021: ​ ​ ​ ​ Fiscal Year: ​ ​ ​ 2021 ​ 14,996 2022 ​ ​ 13,000 2023 ​ ​ 13,000 2024 ​ ​ 73,000 Total debt maturities ​ ​ 113,996 Issuance costs and debt discounts ​ ​ (822) Net carrying value ​ $ 113,174

GOODWILL AND OTHER INTANGIBLE_2

GOODWILL AND OTHER INTANGIBLE ASSETS (Tables)	12 Months Ended
	Jan. 01, 2021
GOODWILL AND OTHER INTANGIBLE ASSETS
Schedule of changes in the carrying value of goodwill by reporting unit	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 27, ​ Additional ​ Additions / ​ January 1, ​ 2019 Purchase Cost Adjustments 2021 ​ ​ (in thousands) Reporting Unit: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Energy ​ $ 126,898 ​ $ — ​ $ 2,477 ​ $ 129,375 Engineering and Consulting ​ ​ 749 ​ ​ — ​ ​ — ​ ​ 749 ​ ​ $ 127,647 ​ $ — ​ $ 2,477 ​ $ 130,124 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 28, ​ Additional ​ Additions / ​ December 27, ​ 2018 Purchase Cost Adjustments 2019 ​ ​ (in thousands) Reporting Unit: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Energy ​ $ 96,999 ​ $ 39,690 ​ $ (9,791) ​ $ 126,898 Engineering and Consulting ​ ​ 749 ​ ​ ​ ​ ​ ​ ​ ​ 749 ​ ​ $ 97,748 ​ $ 39,690 ​ $ (9,791) ​ $ 127,647
Schedule of gross amounts and accumulated amortization of the Company's acquired identifiable intangible assets with finite useful lives	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ January 1, 2021 ​ December 27, 2019 ​ ​ ​ ​ ​ ​ ​ ​ Gross ​ Accumulated ​ Gross ​ Accumulated ​ Amortization ​ Amount Amortization Amount Amortization Period ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (in years) Finite: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Backlog ​ $ 7,944 ​ $ 6,249 ​ $ 7,134 ​ $ 3,763 ​ 1.0 Tradename ​ 15,911 ​ 6,984 ​ 13,351 ​ 4,882 2.5 ​ - ​ 6.0 Non-compete agreements ​ ​ 1,420 ​ ​ 1,390 ​ ​ 2,320 ​ ​ 1,384 ​ 4.0 ​ - ​ 5.0 Developed technology ​ ​ 15,500 ​ ​ 6,107 ​ ​ 14,620 ​ ​ 3,227 ​ 8.0 Customer relationships ​ 58,149 ​ ​ 14,248 ​ ​ 60,733 ​ ​ 8,065 5.0 ​ - ​ 8.0 Total finite intangible assets ​ $ 98,924 ​ $ 34,978 ​ $ 98,158 ​ $ 21,321 ​ ​ ​ ​ ​ ​ In-process research and technology (1) ​ ​ 310 ​ ​ — ​ ​ — ​ ​ — ​ ​ ​ ​ ​ ​ Total intangible assets ​ $ 99,234 ​ $ 34,978 ​ $ 98,158 ​ $ 21,321 ​ ​ ​ ​ ​ ​ ​ (1) In-process research and technology is not amortized until put into use.
Schedule of estimated amortization expense for acquired identifiable intangible assets	​ ​ ​ ​ ​ ​ ​ ​ Future Intangible Asset ​ ​ ​ Amortization expense ​ ​ ​ (in thousands) Fiscal year: ​ ​ ​ 2021 ​ ​ 11,543 2022 ​ 11,227 2023 ​ 9,928 2024 ​ ​ 6,806 2025 ​ ​ 6,235 Thereafter ​ ​ 18,517 ​ ​ $ 64,256

LEASES (Tables)

LEASES (Tables)	12 Months Ended
	Jan. 01, 2021
LEASES
Summary of the lease expense	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fiscal Year ​ ​ 2020 2019 ​ ​ (in thousands) Operating lease cost ​ $ 7,031 ​ $ 5,053 Finance lease cost: ​ ​ ​ ​ ​ ​ Amortization of assets ​ ​ 589 ​ ​ 509 Interest on lease liabilities ​ ​ 29 ​ ​ 36 Total net lease cost ​ $ 7,649 ​ $ 5,598
Summary of lease information presented on the Company's condensed consolidated balance sheet	​ ​ ​ ​ ​ ​ ​ ​ ​ January 1, ​ December 27, ​ ​ 2021 2019 ​ ​ (in thousands) ​ Operating leases: ​ ​ ​ ​ ​ ​ Right-of-use assets $ 20,130 ​ $ 22,297 ​ ​ ​ ​ ​ ​ Lease liability $ 5,844 ​ $ 5,550 ​ Lease liability, less current portion 15,649 ​ 18,411 ​ Total lease liabilities $ 21,493 ​ $ 23,961 ​ ​ ​ ​ ​ ​ Finance leases (included in equipment and leasehold improvements, net): ​ ​ ​ ​ ​ ​ Equipment and leasehold improvements, net $ 2,370 ​ $ 1,957 ​ Accumulated depreciation (1,826) ​ (1,291) ​ Total equipment and leasehold improvements, net $ 544 ​ $ 666 ​ ​ ​ ​ ​ ​ Finance lease obligations $ 248 ​ $ 375 ​ Finance lease obligations, less current portion ​ 236 ​ ​ 191 ​ Total finance lease obligations $ 484 ​ $ 566 ​ ​ ​ ​ ​ ​ ​ ​ Weighted average remaining lease term (in years): ​ ​ ​ ​ ​ ​ Operating Leases ​ 4.40 ​ ​ 4.59 ​ Finance Leases ​ 2.02 ​ ​ 1.47 ​ ​ ​ ​ ​ ​ ​ ​ Weighted average discount rate: ​ ​ ​ ​ ​ ​ Operating Leases ​ 4.44 % ​ 5.14 % Finance Leases ​ 3.74 % ​ 4.80 %
Summary of other information and supplemental cash flow information related to finance and operating leases	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fiscal Year ​ 2020 2019 ​ ​ (in thousands) Cash paid for amounts included in the measurement of lease liabilities: ​ ​ ​ ​ ​ ​ Operating cash flow from operating leases ​ $ 6,972 ​ $ 5,151 Operating cash flow from finance leases ​ ​ 29 ​ ​ 36 Financing cash flow from finance leases ​ ​ 549 ​ ​ 639 ​ ​ ​ ​ ​ ​ ​ Right-of-use assets obtained in exchange for lease liabilities: ​ ​ ​ ​ ​ ​ Operating leases ​ $ 3,186 ​ $ 4,918
Summary of the maturities of operating lease liabilities	The following is a summary of the maturities of lease liabilities as of January 1, 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating Finance ​ ​ (in thousands) ​ Fiscal year: ​ ​ ​ ​ ​ ​ ​ 2021 ​ $ 6,645 ​ $ 261 ​ 2022 ​ 5,818 ​ 172 ​ 2023 ​ 3,983 ​ ​ 54 ​ 2024 ​ ​ 2,611 ​ ​ 14 ​ 2025 ​ ​ 2,088 ​ 2 ​ 2026 and thereafter ​ 2,489 ​ — ​ Total lease payments ​ $ 23,634 ​ $ 503 ​ Less: Imputed interest ​ (2,141) ​ ​ (19) ​ Total lease obligations ​ 21,493 ​ ​ 484 ​ Less: Current obligations ​ 5,844 ​ ​ 248 ​ Noncurrent lease obligations ​ $ 15,649 ​ $ 236 ​
Summary of the maturities of finance lease liabilities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating Finance ​ ​ (in thousands) ​ Fiscal year: ​ ​ ​ ​ ​ ​ ​ 2021 ​ $ 6,645 ​ $ 261 ​ 2022 ​ 5,818 ​ 172 ​ 2023 ​ 3,983 ​ ​ 54 ​ 2024 ​ ​ 2,611 ​ ​ 14 ​ 2025 ​ ​ 2,088 ​ 2 ​ 2026 and thereafter ​ 2,489 ​ — ​ Total lease payments ​ $ 23,634 ​ $ 503 ​ Less: Imputed interest ​ (2,141) ​ ​ (19) ​ Total lease obligations ​ 21,493 ​ ​ 484 ​ Less: Current obligations ​ 5,844 ​ ​ 248 ​ Noncurrent lease obligations ​ $ 15,649 ​ $ 236 ​

SEGMENT AND GEOGRAPHICAL INFO_2

SEGMENT AND GEOGRAPHICAL INFORMATION (Tables)	12 Months Ended
	Jan. 01, 2021
SEGMENT AND GEOGRAPHICAL INFORMATION
Schedule of financial information with respect to the reportable segments	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Engineering ​ Unallocated ​ ​ ​ ​ Consolidated ​ ​ Energy & Consulting Corporate Intersegment Total ​ ​ (in thousands) Fiscal Year 2020 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Contract revenue ​ $ 324,178 ​ $ 66,802 ​ $ — ​ $ — ​ $ 390,980 Depreciation and amortization ​ 17,666 ​ 1,077 ​ ​ — ​ ​ — ​ ​ 18,743 Interest expense ​ 32 ​ — ​ ​ 5,036 ​ ​ — ​ ​ 5,068 Segment profit (loss) before income tax expense ​ (9,963) ​ 9,500 ​ ​ (19,206) ​ — ​ (19,669) Income tax (benefit) expense ​ (2,621) ​ 2,499 ​ ​ (5,051) ​ — ​ ​ (5,173) Net income (loss) ​ (7,343) ​ 7,002 ​ ​ (14,155) ​ — ​ (14,496) Segment assets (1) ​ 337,739 ​ 21,796 ​ ​ 73,918 ​ (23,130) ​ 410,323 Fiscal Year 2019 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Contract revenue ​ $ 370,715 ​ $ 72,384 ​ $ — ​ $ — ​ $ 443,099 Depreciation and amortization ​ 13,703 ​ 1,324 ​ ​ — ​ ​ — ​ ​ 15,027 Interest expense ​ 32 ​ — ​ ​ 4,868 ​ ​ — ​ ​ 4,900 Segment profit (loss) before income tax expense ​ 11,971 ​ 8,839 ​ ​ (16,154) ​ — ​ 4,656 Income tax (benefit) expense ​ 3,308 ​ 2,442 ​ ​ (5,935) ​ — ​ ​ (185) Net income (loss) ​ 8,664 ​ 6,397 ​ ​ (10,220) ​ — ​ 4,841 Segment assets (1) ​ 392,362 ​ 23,682 ​ ​ 46,999 ​ (23,130) ​ 439,913 Fiscal Year 2018 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Contract revenue ​ $ 196,833 ​ $ 75,419 ​ $ — ​ $ — ​ $ 272,252 Depreciation and amortization ​ ​ 5,274 ​ 786 ​ ​ — ​ ​ — ​ ​ 6,060 Interest expense ​ ​ 312 ​ 388 ​ ​ — ​ ​ — ​ ​ 700 Segment profit before income tax expense ​ ​ 8,959 ​ 7,589 ​ ​ (4,387) ​ — ​ 12,161 Income tax expense (benefit) ​ ​ 1,570 ​ 1,330 ​ ​ (769) ​ — ​ ​ 2,131 Net income (loss) ​ ​ 7,390 ​ 6,259 ​ ​ (3,619) ​ — ​ 10,030 Segment assets (1) ​ ​ 252,124 ​ 20,402 ​ ​ 51,515 ​ (23,130) ​ 300,911 (1) Segment assets are presented net of intercompany receivables.
Schedule of disaggregation of revenue	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2020 ​ Energy Engineering and Total ​ (in thousands) Contract Type ​ ​ ​ ​ ​ ​ ​ ​ ​ Time-and-materials ​ $ 47,912 ​ $ 53,840 ​ $ 101,752 Unit-based ​ ​ 170,991 ​ ​ 9,195 ​ ​ 180,186 Fixed price ​ ​ 105,275 ​ ​ 3,767 ​ ​ 109,042 Total ​ $ 324,178 ​ $ 66,802 ​ $ 390,980 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Client Type ​ ​ ​ ​ ​ ​ ​ ​ ​ Commercial ​ $ 36,212 ​ $ 5,155 ​ $ 41,367 Government ​ ​ 93,821 ​ ​ 61,412 ​ ​ 155,233 Utilities ​ ​ 194,145 ​ ​ 235 ​ ​ 194,380 Total ​ $ 324,178 ​ $ 66,802 ​ $ 390,980 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Geography (1) ​ ​ ​ ​ ​ ​ ​ ​ ​ Domestic ​ $ 324,178 ​ $ 66,802 ​ $ 390,980 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2019 ​ Energy Engineering and Total ​ (in thousands) Contract Type ​ ​ ​ ​ ​ ​ ​ ​ ​ Time-and-materials ​ $ 18,625 ​ $ 54,560 ​ $ 73,185 Unit-based ​ ​ 272,978 ​ ​ 14,391 ​ ​ 287,369 Fixed price ​ ​ 79,112 ​ ​ 3,433 ​ ​ 82,545 Total ​ $ 370,715 ​ $ 72,384 ​ $ 443,099 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Client Type ​ ​ ​ ​ ​ ​ ​ ​ ​ Commercial ​ $ 39,311 ​ $ 4,895 ​ $ 44,206 Government ​ ​ 57,020 ​ ​ 67,049 ​ ​ 124,069 Utilities ​ ​ 274,384 ​ ​ 440 ​ ​ 274,824 Total ​ $ 370,715 ​ $ 72,384 ​ $ 443,099 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Geography (1) ​ ​ ​ ​ ​ ​ ​ ​ ​ Domestic ​ $ 370,715 ​ $ 72,384 ​ $ 443,099 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2018 ​ Energy Engineering and Total ​ (in thousands) Contract Type ​ ​ ​ ​ ​ ​ ​ ​ ​ Time-and-materials ​ $ 13,790 ​ $ 59,744 ​ $ 73,534 Unit-based ​ ​ 113,749 ​ ​ 13,300 ​ ​ 127,049 Fixed price ​ ​ 69,294 ​ ​ 2,375 ​ ​ 71,669 Total ​ $ 196,833 ​ $ 75,419 ​ $ 272,252 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Client Type ​ ​ ​ ​ ​ ​ ​ ​ ​ Commercial ​ $ 20,715 ​ $ 4,882 ​ $ 25,597 Government ​ ​ 62,897 ​ ​ 70,091 ​ ​ 132,988 Utilities ​ ​ 113,221 ​ ​ 446 ​ ​ 113,667 Total ​ $ 196,833 ​ $ 75,419 ​ $ 272,252 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Geography (1) ​ ​ ​ ​ ​ ​ ​ ​ ​ Domestic ​ $ 196,833 ​ $ 75,419 ​ $ 272,252 (1) Revenue from our foreign operations were immaterial for fiscal years 2020 and 2019. For fiscal year 2018, we did not have any foreign revenues.
Schedule of assets included in Unallocated Corporate	​ ​ ​ ​ ​ ​ ​ ​ ​ 2020 2019 ​ ​ (in thousands) Assets: ​ ​ ​ ​ ​ ​ Cash and cash equivalents ​ $ 28,405 ​ $ 5,452 Accounts Receivable, net ​ ​ (4,845) ​ ​ (108) Prepaid expenses ​ 2,422 ​ 1,912 Intercompany receivables ​ 691,440 ​ 125,126 Goodwill ​ ​ 2 ​ ​ 2 Other receivables ​ 4,409 ​ 3,915 Equipment and leasehold improvements, net ​ 1,585 ​ 1,637 Investments in subsidiaries ​ 26,576 ​ 23,130 ROU Assets ​ ​ 809 ​ ​ 1,141 Other ​ 444 ​ 606 Deferred income taxes ​ ​ 14,111 ​ ​ 9,312 ​ ​ $ 765,358 ​ $ 172,125

SHAREHOLDERS' EQUITY (Tables)

SHAREHOLDERS' EQUITY (Tables)	12 Months Ended
	Jan. 01, 2021
Summary of option activity and changes during the period	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted- ​ ​ ​ ​ Weighted- ​ Average ​ ​ ​ ​ Average ​ Remaining ​ ​ ​ ​ Exercise ​ Contractual ​ Options Price Term ​ ​ (in thousands) ​ ​ ​ ​ (in years) ​ Outstanding at December 27, 2019 1,124 ​ $ 17.80 6.06 ​ Granted — ​ — — ​ Exercised (119) ​ 9.12 — ​ Forfeited or expired (2) ​ 2.71 — ​ Outstanding at January 1, 2021 1,003 ​ $ 18.86 5.43 ​ Vested and expected to vest at January 1, 2021 1,003 ​ $ 18.86 5.43 ​ Exercisable at January 1, 2021 952 ​ $ 18.16 5.31 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted- ​ ​ ​ ​ ​ Weighted- ​ Average ​ ​ ​ ​ Average ​ Remaining ​ ​ ​ ​ Exercise ​ Contractual ​ Options Price Term ​ ​ (in thousands) ​ ​ ​ ​ (in years) ​ Outstanding at December 28, 2018 1,252 ​ $ 16.87 6.62 ​ Granted — ​ — — ​ Exercised (115) ​ 8.08 — ​ Forfeited or expired (13) ​ 14.97 — ​ Outstanding at December 27, 2019 1,124 ​ $ 17.80 6.06 ​ Vested and expected to vest at December 27, 2019 1,124 ​ $ 17.80 6.06 ​ Exercisable at December 27, 2019 958 ​ $ 15.48 5.68 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted- ​ ​ ​ ​ Weighted- ​ Average ​ ​ ​ ​ Average ​ Remaining ​ ​ ​ ​ Exercise ​ Contractual ​ Options Price Term ​ ​ (in thousands) ​ ​ ​ ​ (in years) ​ Outstanding at December 29, 2017 1,207 ​ $ 14.04 7.02 ​ Granted 158 ​ 31.54 — ​ Exercised (85) ​ 7.85 — ​ Forfeited or expired (28) ​ 5.07 — ​ Outstanding at December 28, 2018 1,252 ​ $ 16.87 6.62 ​ Vested and expected to vest at December 28, 2018 1,252 ​ $ 16.87 6.62 ​ Exercisable at December 28, 2018 838 ​ $ 12.20 5.58 ​
Summary of the status of the nonvested options and changes in nonvested options	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted- ​ ​ ​ ​ Average ​ ​ ​ ​ Grant-Date ​ Options Fair Value ​ ​ (in thousands) ​ ​ ​ ​ Nonvested at December 27, 2019 166 ​ $ 12.15 ​ Granted — ​ — ​ Vested (114) ​ 30.97 ​ Forfeited — ​ — ​ Nonvested at January 1, 2021 52 ​ 31.73 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted- ​ ​ ​ ​ ​ Average ​ ​ ​ ​ Grant-Date ​ Options Fair Value ​ ​ (in thousands) ​ ​ ​ ​ Nonvested at December 28, 2018 414 ​ $ 8.69 ​ Granted — ​ — ​ Vested (242) ​ 9.43 ​ Forfeited (6) ​ 10.87 ​ Nonvested at December 27, 2019 166 ​ 12.15 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted- ​ ​ ​ ​ ​ Average ​ ​ ​ ​ Grant-Date ​ Options Fair Value ​ ​ (in thousands) ​ ​ ​ ​ Nonvested at December 29, 2017 547 ​ $ 6.43 ​ Granted 158 ​ 12.73 ​ Vested (263) ​ 7.29 ​ Forfeited (28) ​ 5.07 ​ Nonvested at December 28, 2018 414 ​ 8.69 ​
Schedule of assumptions	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2019 2018 Expected volatility 34 % 37 % - 38 % Expected dividends 0 % ​ ​ ​ 0 % Expected term (in years) 6 ​ ​ ​ ​ 6 ​ Risk-free rate 2.49 % 2.65 % - 2.78 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2020 ​ ​ 2019 ​ ​ 2018 ​ Weighted-average expected term (in years) ​ .5 ​ ​ ​ .5 ​ ​ ​ .5 ​ Risk-Free interest Rate ​ 0.9 % ​ ​ 2.3 % ​ ​ 1.4 % Stock Price Volatility ​ 30.3 % ​ ​ 35.6 % ​ ​ 37.9 % Dividend yield ​ 0 % ​ ​ 0 % ​ ​ 0 % Fair Value ​ $ 28.39 ​ ​ $ 33.01 ​ ​ $ 26.86 ​
Restricted stock
Summary of restricted stock activity	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted- ​ ​ ​ ​ Average ​ Restricted Stock Grant Date ​ ​ (in thousands) ​ ​ ​ ​ Outstanding at December 27, 2019 ​ 58 ​ $ 33.33 Awarded ​ 99 ​ 32.89 ​ Vested ​ (29) ​ 32.35 ​ Forfeited ​ — ​ — ​ Outstanding at January 1, 2021 ​ 128 ​ $ 33.21 ​ ​ ​ ​ ​ ​ ​ ​ Outstanding at December 28, 2018 ​ 64 ​ $ 22.28 Awarded ​ 37 ​ 35.60 ​ Vested ​ (43) ​ 18.90 ​ Forfeited ​ — ​ — ​ Outstanding at December 27, 2019 ​ 58 ​ $ 33.33 ​ ​ ​ ​ ​ ​ ​ ​ Outstanding at December 29, 2017 ​ 87 ​ $ 17.67 ​ Awarded ​ 22 ​ 28.17 ​ Vested ​ (45) ​ 16.09 ​ Forfeited ​ — ​ — ​ Outstanding at December 28, 2018 ​ 64 ​ $ 22.28 ​
Performance Shares
Summary of restricted stock activity	​ ​ ​ ​ ​ ​ ​ ​ ​ Performance-Based ​ Weighted-Average ​ Restricted Stock Unit Grant Date Fair Value ​ ​ (in thousands) ​ ​ ​ Outstanding at December 27, 2019 ​ 431 ​ $ 20.68 Awarded ​ 413 ​ 29.22 Released ​ (447) ​ 28.26 Forfeited ​ (18) ​ 28.62 Outstanding at January 1, 2021 ​ 379 ​ $ 20.68 ​ ​ ​ ​ ​ ​ Outstanding at December 28, 2018 ​ 280 ​ $ 21.94 Awarded ​ 329 ​ 28.99 Released ​ (175) ​ 38.20 Forfeited ​ (3) ​ 27.28 Outstanding at December 27, 2019 ​ 431 ​ $ 20.68 ​ ​ ​ ​ ​ ​ Outstanding at December 28, 2018 ​ — ​ $ — Awarded ​ 280 ​ 21.94 Released ​ — ​ — Forfeited ​ — ​ — Outstanding at December 27, 2019 ​ 280 ​ $ 21.94

INCOME TAXES (Tables)

INCOME TAXES (Tables)	12 Months Ended
	Jan. 01, 2021
INCOME TAXES
Schedule of provision for income taxes	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fiscal Year ​ 2020 2019 2018 ​ ​ (in thousands) ​ Current federal taxes ​ $ (592) ​ $ (548) ​ $ 3,632 ​ Current state taxes ​ 166 ​ 551 ​ 1,389 ​ Current foreign taxes ​ ​ 18 ​ ​ — ​ ​ — ​ Deferred federal taxes ​ (2,939) ​ (159) ​ (2,539) ​ Deferred state taxes ​ (1,826) ​ (29) ​ (351) ​ ​ ​ $ (5,173) ​ $ (185) ​ $ 2,131 ​
Schedule of sources and tax effects of the differences	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2020 2019 2018 ​ ​ (in thousands) ​ Computed “expected” federal income tax expense ​ $ (4,130) ​ $ 977 ​ $ 2,554 ​ Permanent differences ​ 122 ​ 163 ​ 77 ​ Nondeductible Executive Compensation ​ ​ 1,386 ​ ​ 688 ​ ​ — ​ Stock options and disqualifying dispositions ​ ​ 4 ​ ​ (731) ​ ​ (354) ​ Energy efficient building deduction ​ ​ (738) ​ ​ (1,291) ​ ​ (919) ​ Current and deferred state income tax expense, net of federal benefit ​ (1,205) ​ 466 ​ 815 ​ Federal deferred tax adjustments ​ ​ — ​ ​ 231 ​ ​ 220 ​ Adjustment for uncertain tax positions ​ ​ (142) ​ ​ (282) ​ ​ 61 ​ Research and development tax credit ​ ​ (527) ​ ​ (510) ​ ​ (313) ​ Adjustment to prior earn-out liability ​ ​ — ​ ​ — ​ ​ (198) ​ Non-deductible transaction expenses ​ ​ — ​ ​ — ​ ​ 203 ​ Other ​ 57 ​ 27 ​ (15) ​ True up income tax accounts ​ ​ — ​ ​ 77 ​ ​ — ​ ​ ​ $ (5,173) ​ $ (185) ​ $ 2,131 ​
Schedule of the tax effects of temporary differences that give rise to significant portions of the net deferred tax assets and liabilities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ January 1, ​ December 27, ​ 2021 2019 ​ ​ (in thousands) Deferred tax assets: ​ ​ ​ ​ ​ ​ Accounts receivable allowance ​ $ 199 ​ $ 315 Other accrued liabilities ​ ​ 1,676 ​ ​ 2,124 Federal and state net operating losses ​ ​ 18,854 ​ ​ 18,717 Lease Liability ​ ​ 5,856 ​ ​ 6,467 Stock compensation ​ ​ 3,063 ​ ​ 3,381 Adjustments to fair value of assets ​ ​ 56 ​ ​ 79 Credit Carryforwards ​ ​ 496 ​ ​ — Other ​ 211 ​ 622 ​ ​ 30,411 ​ 31,705 Valuation allowance ​ (86) ​ (86) Net deferred tax assets ​ $ 30,325 ​ $ 31,619 Deferred tax liabilities: ​ ​ ​ ​ ​ ​ Deferred revenue ​ $ (2,999) ​ $ (5,031) Fixed assets ​ ​ (732) ​ ​ (618) Intangible assets ​ ​ (6,796) ​ ​ (10,077) Lease right-of-use assets ​ ​ (5,484) ​ ​ (6,127) Other ​ ​ (203) ​ ​ (454) ​ ​ (16,214) ​ (22,307) Net deferred tax asset ​ $ 14,111 ​ $ 9,312
Schedule of uncertain tax positions	​ ​ ​ ​ ​ ​ Amount ​ ​ (in thousands) Balance as of December 27, 2019 ​ $ 142 Additions based on tax positions related to the current year ​ — Additions for tax positions of prior years ​ ​ — Reductions for tax positions related to the current year ​ ​ — Reductions for tax positions of prior years ​ ​ (142) Balance as of January 1, 2021 ​ $ —

EARNINGS PER SHARE (EPS) (Table

EARNINGS PER SHARE (EPS) (Tables)	12 Months Ended
	Jan. 01, 2021
EARNINGS PER SHARE (EPS)
Schedule of number of weighted-average common shares outstanding used to compute basic and diluted EPS	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fiscal Year ​ ​ 2020 2019 2018 ​ ​ (in thousands, except per share amounts) Net income (loss) ​ $ (14,496) ​ $ 4,841 ​ $ 10,030 Weighted-average common shares outstanding ​ 11,793 ​ 11,162 ​ 9,264 Effect of dilutive stock options and restricted stock awards ​ — ​ 604 ​ 499 Weighted-average common shares outstanding-diluted ​ 11,793 ​ 11,766 ​ 9,763 Earnings (Loss) per share: ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic ​ $ (1.23) ​ $ 0.43 ​ $ 1.08 Diluted ​ $ (1.23) ​ $ 0.41 ​ $ 1.03

BUSINESS COMBINATIONS (Tables)

BUSINESS COMBINATIONS (Tables)	12 Months Ended
	Jan. 01, 2021
E3, Inc.
Schedule of consideration for the acquisition	​ ​ ​ ​ ​ ​ E3, Inc. ​ ​ ​ (in thousands) Cash paid ​ $ 27,000 Other working capital adjustment ​ ​ 1,780 Issuance of common stock ​ ​ 5,000 Contingent Consideration ​ ​ 6,000 Total consideration ​ $ 39,780
Schedule of amounts for the acquired assets and liabilities recorded at their estimated fair value as of the acquisition date	​ ​ ​ ​ ​ ​ E3, Inc. ​ ​ ​ (in thousands) Current assets ​ $ 5,278 Non-current assets (1) ​ ​ 341 Cash ​ ​ 2,264 Equipment and leasehold improvements, net ​ ​ 409 Right-of-use assets ​ ​ 7,641 Current lease liability ​ ​ (750) Non-current lease liability ​ ​ (6,890) Liabilities ​ ​ (4,325) Backlog ​ ​ 2,600 Customer relationships ​ ​ 6,050 Tradename ​ ​ 4,200 Developed technology ​ ​ 880 In-progress research & development ​ ​ 310 Goodwill ​ ​ 21,772 Net assets acquired ​ $ 39,780 (1) Excluded from non-current assets are equipment and leasehold improvements, net, right-of-use assets, customer relationships, tradename, backlog and goodwill.
Onsite Energy Corporation
Schedule of consideration for the acquisition	​ ​ ​ ​ ​ ​ Onsite Energy ​ ​ ​ (in thousands) Cash paid ​ $ 24,905 Other working capital adjustment ​ ​ - Total consideration ​ $ 24,905 ​ ​ ​ ​
Schedule of amounts for the acquired assets and liabilities recorded at their estimated fair value as of the acquisition date	​ ​ ​ ​ ​ ​ Onsite Energy ​ ​ ​ (in thousands) Current assets ​ $ 19,058 Non-current assets (1) ​ ​ 10 Equipment and leasehold improvements, net ​ ​ 39 Right-of-use assets ​ ​ 828 Current lease liability ​ ​ (168) Non-current lease liability ​ ​ (660) Liabilities ​ ​ (12,222) Backlog ​ ​ 1,510 Customer relationships ​ ​ 7,050 Tradename ​ ​ 860 Goodwill ​ ​ 8,600 Net assets acquired ​ $ 24,905 (1) Excluded from non-current assets are equipment and leasehold improvements, net, right-of-use assets, customer relationships, tradename, backlog and goodwill.
The Weidt Group
Schedule of consideration for the acquisition	​ ​ ​ ​ ​ ​ The Weidt Group ​ ​ ​ (in thousands) Cash paid ​ $ 22,136 Other working capital adjustment ​ ​ - Total consideration ​ $ 22,136
Schedule of amounts for the acquired assets and liabilities recorded at their estimated fair value as of the acquisition date	​ ​ ​ ​ ​ ​ The Weidt Group ​ ​ ​ (in thousands) Current assets ​ $ 2,317 Non-current assets (1) ​ ​ 25 Equipment and leasehold improvements, net ​ ​ 198 Right-of-use assets ​ ​ 1,730 Current lease liability ​ ​ (245) Non-current lease liability ​ ​ (1,533) Liabilities ​ ​ (612) Backlog ​ ​ 750 Customer relationships ​ ​ 4,240 Tradename ​ ​ 550 Developed technology ​ ​ 3,170 Goodwill ​ ​ 11,546 Net assets acquired ​ $ 22,136 (1) Excluded from non-current assets are equipment and leasehold improvements, net, right-of-use assets, customer relationships, tradename, developed technology, backlog and goodwill.
Lime Energy
Schedule of unaudited pro forma financial information	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fiscal Year ​ 2020 2019 ​ ​ (in thousands, except per share data) Pro forma revenue ​ $ 390,980 ​ $ 471,330 ​ ​ ​ ​ ​ ​ ​ Pro forma income (loss) from operations ​ $ (16,227) ​ $ 10,846 Pro forma net loss (1) ​ $ (14,496) ​ $ (16,618) ​ ​ ​ ​ ​ ​ ​ Loss per share: ​ ​ ​ ​ ​ ​ Basic ​ $ (1.23) ​ $ (1.49) Diluted ​ $ (1.23) ​ $ (1.41) ​ ​ ​ ​ ​ ​ ​ Weighted average shares outstanding: ​ ​ ​ ​ ​ ​ Basic ​ ​ 11,793 ​ ​ 11,162 Diluted ​ ​ 11,793 ​ ​ 11,766 (1) Adjustments to pro forma net income include income from operations, amortization and interest expenses.

QUARTERLY FINANCIAL INFORMATI_2

QUARTERLY FINANCIAL INFORMATION (UNAUDITED) (Tables)	12 Months Ended
	Jan. 01, 2021
QUARTERLY FINANCIAL INFORMATION (UNAUDITED)
Schedule of selected quarterly information	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fiscal Three Months Ended ​ ​ April 3, ​ July 3, ​ October 2, ​ January 1, ​ 2020 2020 2020 2021 ​ ​ (in thousands except per share amounts) Contract revenue ​ $ 106,026 ​ $ 83,549 ​ $ 104,508 ​ $ 96,897 ​ Income (loss) from operations ​ (8,269) ​ (3,841) ​ 1,601 ​ (5,718) ​ Income tax benefit ​ (1,605) ​ (90) ​ (1,586) ​ (1,892) ​ Net income (loss) ​ (8,154) ​ (4,985) ​ 2,640 ​ (3,997) ​ Earnings (loss) per share: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic ​ $ (0.71) ​ $ (0.43) ​ $ 0.22 ​ $ (0.33) ​ Diluted ​ $ (0.71) ​ $ (0.43) ​ $ 0.21 ​ $ (0.33) ​ Weighted-average shares outstanding: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic ​ 11,510 ​ 11,682 ​ 11,992 ​ 12,011 ​ Diluted ​ 11,510 ​ 11,682 ​ 12,417 ​ 12,011 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fiscal Three Months Ended ​ ​ March 29, ​ June 28, ​ September 27, ​ December 27, ​ 2019 2019 2019 2019 ​ ​ (in thousands except per share amounts ) Contract revenue ​ $ 91,793 ​ $ 104,396 ​ $ 117,494 ​ $ 129,416 ​ Income (loss) from operations ​ (234) ​ 2,773 ​ 1,295 ​ 5,529 ​ Income tax expense (benefit) ​ (927) ​ (70) ​ (376) ​ 1,188 ​ Net income (loss) ​ (417) ​ 1,640 ​ 416 ​ 3,202 ​ Earnings (loss) per share: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic ​ $ (0.04) ​ $ 0.15 ​ $ 0.04 ​ $ 0.28 ​ Diluted ​ $ (0.04) ​ $ 0.14 ​ $ 0.04 ​ $ 0.27 ​ Weighted-average shares outstanding: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic ​ 10,974 ​ 11,100 ​ 11,217 ​ 11,357 ​ Diluted ​ 10,974 ​ 11,679 ​ 11,789 ​ 11,913 ​

ORGANIZATION AND OPERATIONS O_4

ORGANIZATION AND OPERATIONS OF THE COMPANY (Details)

Mar. 11, 2021contract

Jan. 01, 2021

Oct. 02, 2020

Jul. 03, 2020

Apr. 03, 2020

Dec. 27, 2019

Sep. 27, 2019

Jun. 28, 2019

Mar. 29, 2019

Dec. 28, 2018

Sep. 28, 2018

Jun. 29, 2018

Mar. 30, 2018

Jan. 01, 2021

Jan. 01, 2021segment

Dec. 27, 2019

Dec. 28, 2018

Summary of Significant Accounting Policies [Line Items]

Number of reporting segments | segment

2

Length of fiscal period

91 days

91 days

91 days

98 days

91 days

91 days

91 days

91 days

91 days

91 days

91 days

91 days

91 days

53 days

364 days

364 days

Number of contracts cancelled | contract

0

Energy Segment

Summary of Significant Accounting Policies [Line Items]

Percentage of revenue considered nonessential

40.00%

Other Energy

Summary of Significant Accounting Policies [Line Items]

Percentage of revenue considered essential

60.00%

Minimum

Summary of Significant Accounting Policies [Line Items]

Length of fiscal period

91 days

364 days

Maximum

Summary of Significant Accounting Policies [Line Items]

Length of fiscal period

98 days

371 days

ORGANIZATION AND OPERATIONS O_5

ORGANIZATION AND OPERATIONS OF THE COMPANY - Accounting for Contracts (Details)	12 Months Ended
	Jan. 01, 2021USD ($)segment	Dec. 27, 2019USD ($)	Dec. 28, 2018USD ($)
Accounting for Contracts
Number of reportable segments | segment	2
Costs of contract revenue
Payroll taxes, bonuses and employee benefit costs for all Company personnel	$ 71,229,000	$ 66,303,000	$ 45,248,000
Revenue of the entity recorded in which it acts solely in the capacity of an agent	0
Costs recorded for costs to the entity in which it acts solely in the capacity of an agent	$ 0
Maximum
Costs of contract revenue
Percent of revenue (as a percent)	3.00%
Property, Plant and Equipment, Useful Life	5 years
Minimum
Costs of contract revenue
Percent of revenue (as a percent)	2.00%
Property, Plant and Equipment, Useful Life	2 years
Accounts receivable
Costs of contract revenue
Retained accounts receivable	$ 6,200,000	$ 5,400,000
Cost of Sales
Costs of contract revenue
Payroll taxes, bonuses and employee benefit costs for all Company personnel	0
Allocation of facilities costs to contract revenue	$ 0

ORGANIZATION AND OPERATIONS O_6

ORGANIZATION AND OPERATIONS OF THE COMPANY- Estimated Useful Lives (Details)	12 Months Ended
	Jan. 01, 2021
Minimum
Equipment and Leasehold Improvements
Estimated useful life	2 years
Maximum
Equipment and Leasehold Improvements
Estimated useful life	5 years
Furniture and fixtures
Equipment and Leasehold Improvements
Estimated useful life	5 years
Computer hardware
Equipment and Leasehold Improvements
Estimated useful life	3 years
Computer software
Equipment and Leasehold Improvements
Estimated useful life	3 years
Automobiles and trucks
Equipment and Leasehold Improvements
Estimated useful life	3 years
Field equipment
Equipment and Leasehold Improvements
Estimated useful life	5 years

ORGANIZATION AND OPERATIONS O_7

ORGANIZATION AND OPERATIONS OF THE COMPANY - Business Combination, Income Taxes and Recent Accounting Pronouncements (Details) - USD ($)	1 Months Ended	3 Months Ended
	Jul. 31, 2020	Apr. 03, 2020	Jan. 01, 2021	Dec. 27, 2019
Income Taxes
Valuation reserve related to California net operating losses			$ 86,000	$ 86,000
Minimum
Management's Plans in Response to Covid-19
Temporary cash wage reduction for salaried employees (as a percent)	0.00%	0.00%
Maximum
Management's Plans in Response to Covid-19
Temporary cash wage reduction for salaried employees (as a percent)	0.00%	75.00%

SUPPLEMENTAL FINANCIAL STATEM_3

SUPPLEMENTAL FINANCIAL STATEMENT DATA - Accounts Receivables (Details) - USD ($) $ in Thousands	Jan. 01, 2021	Dec. 27, 2019	Jan. 01, 2021	Dec. 27, 2019	Dec. 28, 2018	Jan. 01, 2021	Dec. 27, 2019
Accounts receivable
Other assets						$ 4,524	$ 14,075
Total accounts receivable, gross						129,480	174,144
Allowance for doubtful accounts	$ (2,127)	$ (1,147)	$ (1,147)	$ (442)	$ (442)	(2,127)	(1,147)
Total accounts receivable, net						127,353	172,997
Movements in the allowance for doubtful accounts
Balance as of the beginning of the year			1,147	442	369
(Recovery of) provision for doubtful accounts			1,329	1,051	470
Write-offs of uncollectible accounts			(388)	(346)	(397)
Fair value adjustment			39
Balance as of the end of the year	$ 2,127	$ 1,147	2,127	1,147	$ 442
Cash proceeds from sale of trade receivables			$ 10,600	$ 4,900
Other, net
Movements in the allowance for doubtful accounts
Discount on trade accounts receivable sold						1,700	0
Accounts Receivable | Credit concentration risk | Consolidated Edison of New York
Movements in the allowance for doubtful accounts
Customer concentration risk percentage	31.00%
Accounts Receivable | Credit concentration risk | Los Angeles Department Of Water And Power
Movements in the allowance for doubtful accounts
Customer concentration risk percentage		16.00%
Billed
Accounts receivable
Total accounts receivable, gross						62,530	58,651
Unbilled
Accounts receivable
Total accounts receivable, gross						56,262	96,041
Contract retentions
Accounts receivable
Total accounts receivable, gross						$ 6,164	$ 5,377

SUPPLEMENTAL FINANCIAL STATEM_4

SUPPLEMENTAL FINANCIAL STATEMENT DATA - Equipment And Leasehold Improvements, Net (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 01, 2021	Dec. 27, 2019	Dec. 28, 2018
EQUIPMENT AND LEASEHOLD IMPROVEMENTS
Equipment and leasehold improvements, net	$ 30,715	$ 27,334
Accumulated depreciation and amortization	(18,209)	(15,283)
Total equipment and leasehold improvements, net	12,506	12,051
Depreciation	5,000	3,400	$ 1,600
Amortization of assets	589	509
Furniture and fixtures
EQUIPMENT AND LEASEHOLD IMPROVEMENTS
Equipment and leasehold improvements, net	4,088	4,614
Computer hardware and software
EQUIPMENT AND LEASEHOLD IMPROVEMENTS
Equipment and leasehold improvements, net	18,047	14,789
Leasehold improvements
EQUIPMENT AND LEASEHOLD IMPROVEMENTS
Equipment and leasehold improvements, net	2,994	2,410
Equipment under finance lease
EQUIPMENT AND LEASEHOLD IMPROVEMENTS
Equipment and leasehold improvements, net	2,370	1,957
Accumulated depreciation and amortization	(1,826)	(1,291)
Total equipment and leasehold improvements, net	544	666
Amortization of assets	600	500	$ 400
Automobiles, trucks, and field equipment
EQUIPMENT AND LEASEHOLD IMPROVEMENTS
Equipment and leasehold improvements, net	$ 3,216	$ 3,564

SUPPLEMENTAL FINANCIAL STATEM_5

SUPPLEMENTAL FINANCIAL STATEMENT DATA - Accrued Liabilities (Details) - USD ($) $ in Thousands	Jan. 01, 2021	Dec. 27, 2019
ACCRUED LIABILITIES
Accrued subcontractor costs	$ 19,124	$ 45,366
Other	11,981	4,630
Accrued bonuses	5,211	7,756
Employee withholdings	2,768	3,463
Compensation and payroll taxes	1,983	3,286
Paid leave bank	687	3,114
Total accrued liabilities	$ 41,754	$ 67,615

DERIVATIVE FINANCIAL INSTRUME_3

DERIVATIVE FINANCIAL INSTRUMENTS (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Jan. 01, 2021	Jan. 31, 2019
Cash flow hedge
Derivative [Line Items]
Effective portion of interest rate swap designated as cash flow hedge before tax effect		$ 0.7
Interest swap agreement | Forecast
Derivative [Line Items]
Accumulated other comprehensive income to interest expense	$ (0.5)
Interest swap agreement | Cash flow hedge
Derivative [Line Items]
Notional amount			$ 35
Fixed rate (in percent)			2.47%
Accumulated other comprehensive income to interest expense		$ 0

DERIVATIVE FINANCIAL INSTRUME_4

DERIVATIVE FINANCIAL INSTRUMENTS - Fair Values (Details) - Designated as hedging instruments - Interest swap agreement - USD ($) $ in Thousands	Jan. 01, 2021	Dec. 27, 2019
Accrued liabilities.
Derivatives, Fair Value [Line Items]
Fair value of Derivative Instruments	$ (624)	$ (241)
Other noncurrent (liabilities) assets
Derivatives, Fair Value [Line Items]
Fair value of Derivative Instruments	$ (48)	$ (306)

DERIVATIVE FINANCIAL INSTRUME_5

DERIVATIVE FINANCIAL INSTRUMENTS - Others (Details) $ in Millions	12 Months Ended
	Jan. 01, 2021USD ($)
Cash flow hedge
Derivative [Line Items]
Effective portion	$ 0.7

DERIVATIVE FINANCIAL INSTRUME_6

DERIVATIVE FINANCIAL INSTRUMENTS -Accumulated balances and reporting period activities (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 01, 2021	Dec. 27, 2019
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Balances	$ 167,278	$ 144,289
Balances	169,164	167,278
Gain (Loss) on Derivative Instruments
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Balances	(396)
Other comprehensive loss before reclassifications	(126)	(546)
Income tax benefit (expense) related to derivative instruments	34	150
Net current-period other comprehensive loss	(488)	(396)
Balances		(396)
Accumulated Other Comprehensive Loss.
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Balances	(396)
Other comprehensive loss before reclassifications	(126)	(546)
Income tax benefit (expense) related to derivative instruments	34	150
Net current-period other comprehensive loss	(488)	(396)
Balances	$ (488)	$ (396)

DEBT OBLIGATIONS (Details)

DEBT OBLIGATIONS (Details) - USD ($) $ in Thousands	Jan. 01, 2021	Dec. 27, 2019
Debt Obligations
Total debt obligations	$ 113,996	$ 131,060
Issuance costs and debt discounts	(822)	(709)
Total debt maturities	113,174	130,351
Less current portion of long-term debt	(14,996)	(13,720)
Long-term debt portion	98,178	116,631
Term A Loan
Debt Obligations
Total debt obligations	85,000	95,000
Revolving Credit Facility
Debt Obligations
Total debt obligations		5,000
Delayed Draw Term Loan Facility
Debt Obligations
Total debt obligations	27,000	30,000
Other debt agreements
Debt Obligations
Total debt obligations	$ 1,996	$ 1,060

DEBT OBLIGATIONS - Line of cred

DEBT OBLIGATIONS - Line of credit (Details)	Dec. 31, 2020	Dec. 30, 2020	May 06, 2020	May 05, 2020	Sep. 27, 2019USD ($)	Jan. 01, 2021USD ($)	Dec. 27, 2019USD ($)	Dec. 28, 2018USD ($)	Jun. 26, 2019USD ($)	Dec. 20, 2018USD ($)
Debt Instrument [Line Items]
Composite interest rate						2.80%
Letter of credit issued						$ 2,700,000
Borrowings under term loan facility and line of credit						$ 24,000,000	$ 138,000,000	$ 70,000,000
2019 Credit Agreement
Debt Instrument [Line Items]
Minimum fixed charge coverage ratio						1.20
2019 Credit Agreement | Debt Covenant Threshold Tranche One
Debt Instrument [Line Items]
Minimum total leverage ratio		3.50
2019 Credit Agreement | Debt Covenant Threshold Tranche Two
Debt Instrument [Line Items]
Minimum total leverage ratio	3.25
Term A Loan
Debt Instrument [Line Items]
Unamortized debt issuance costs						$ 800,000
Quarterly installments					$ 2,500,000
Term A Loan | BMO
Debt Instrument [Line Items]
Amount borrowed to finance acquisition									$ 100,000,000
Delayed Draw Term Loan Facility
Debt Instrument [Line Items]
Maximum borrowing capacity									50,000,000
Annual amortization of debt (as a Percent)					2.50%
Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity									$ 50,000,000
Revolving Credit Facility | Debt Interest Period Four [Member] | Maximum
Debt Instrument [Line Items]
Commitment fee (as a percent)			0.35%
Revolving Credit Facility | Debt Interest Period Four [Member] | Minimum
Debt Instrument [Line Items]
Commitment fee (as a percent)			0.15%
Delayed Draw Term Loan And Revolving Credit Facility
Debt Instrument [Line Items]
Unamortized debt issuance costs						$ 600,000
Delayed Draw Term Loan And Revolving Credit Facility | Debt Interest Period Three [Member] | Maximum
Debt Instrument [Line Items]
Commitment fee (as a percent)			0.45%
Delayed Draw Term Loan And Revolving Credit Facility | Debt Interest Period Three [Member] | Minimum
Debt Instrument [Line Items]
Commitment fee (as a percent)			0.15%
Third Amendment [Member] | Debt Interest Period Three [Member] | Federal Funds Effective Swap Rate
Debt Instrument [Line Items]
Spread on floating interest rate (as a percent)			0.50%
Third Amendment [Member] | Debt Interest Period Three [Member] | London Interbank Offered Rate One Month LIBOR | Minimum
Debt Instrument [Line Items]
Interest rate at end of period (as a percent)			0.75%
Third Amendment [Member] | Debt Interest Period One [Member] | London Interbank Offered Rate One Month LIBOR
Debt Instrument [Line Items]
Spread on floating interest rate (as a percent)				2.00%
Third Amendment [Member] | Debt Interest Period Four [Member] | London Interbank Offered Rate One Month LIBOR | Minimum
Debt Instrument [Line Items]
Interest rate at end of period (as a percent)			0.00%
Third Amendment [Member] | Base rate | Debt Interest Period Two [Member] | London Interbank Offered Rate One Month LIBOR
Debt Instrument [Line Items]
Spread on floating interest rate (as a percent)			1.50%
Third Amendment [Member] | Base rate | Debt Interest Period Three [Member] | London Interbank Offered Rate One Month LIBOR | Maximum
Debt Instrument [Line Items]
Spread on floating interest rate (as a percent)			1.50%
Third Amendment [Member] | Base rate | Debt Interest Period Three [Member] | London Interbank Offered Rate One Month LIBOR | Minimum
Debt Instrument [Line Items]
Spread on floating interest rate (as a percent)			0.125%
Third Amendment [Member] | Base rate | Debt Interest Period Four [Member] | Maximum
Debt Instrument [Line Items]
Spread on floating interest rate (as a percent)			1.00%
Third Amendment [Member] | Base rate | Debt Interest Period Four [Member] | Minimum
Debt Instrument [Line Items]
Spread on floating interest rate (as a percent)			0.125%
Third Amendment [Member] | LIBOR | Debt Interest Period Two [Member] | London Interbank Offered Rate One Month LIBOR
Debt Instrument [Line Items]
Spread on floating interest rate (as a percent)			2.50%
Third Amendment [Member] | LIBOR | Debt Interest Period Three [Member] | London Interbank Offered Rate One Month LIBOR
Debt Instrument [Line Items]
Spread on floating interest rate (as a percent)			1.00%
Third Amendment [Member] | LIBOR | Debt Interest Period Three [Member] | London Interbank Offered Rate One Month LIBOR | Maximum
Debt Instrument [Line Items]
Spread on floating interest rate (as a percent)			2.50%
Third Amendment [Member] | LIBOR | Debt Interest Period Three [Member] | London Interbank Offered Rate One Month LIBOR | Minimum
Debt Instrument [Line Items]
Spread on floating interest rate (as a percent)			1.125%
Third Amendment [Member] | LIBOR | Debt Interest Period Four [Member] | London Interbank Offered Rate One Month LIBOR | Maximum
Debt Instrument [Line Items]
Spread on floating interest rate (as a percent)			2.00%
Third Amendment [Member] | LIBOR | Debt Interest Period Four [Member] | London Interbank Offered Rate One Month LIBOR | Minimum
Debt Instrument [Line Items]
Spread on floating interest rate (as a percent)			1.125%
Notes payable for insurance
Debt Instrument [Line Items]
Interest rate (as a percent)						2.75%
Interest and principal payments						$ 200,000
Unsecured notes payable						1,100,000
Letters of Credit | Maximum
Debt Instrument [Line Items]
Commitment fee (as a percent)			2.50%
Letters of Credit | Minimum
Debt Instrument [Line Items]
Commitment fee (as a percent)			0.84%
Letters of Credit | Debt Interest Period Four [Member] | Maximum
Debt Instrument [Line Items]
Commitment fee (as a percent)			2.00%
Letters of Credit | Debt Interest Period Four [Member] | Minimum
Debt Instrument [Line Items]
Commitment fee (as a percent)			0.84%
Note Payable Onsite Energy Utility Customer | Utility Customer Agreement
Debt Instrument [Line Items]
Interest rate (as a percent)										4.332%
Unsecured notes payable						800,000	900,000
Amount committed to repay										$ 1,700,000
Notes payable for IBM
Debt Instrument [Line Items]
Interest rate (as a percent)								4.656%
Interest and principal payments								$ 6,315
Notes payable for IBM | Software Agreements
Debt Instrument [Line Items]
Software cost								$ 200,000
Unsecured notes payable						$ 57,000	$ 133,000

DEBT OBLIGATIONS - Debt Agreeme

DEBT OBLIGATIONS - Debt Agreements (Details) $ in Millions	May 06, 2020USD ($)
Third Amendment [Member]
Debt Instrument [Line Items]
Maximum capital expenditure, debt covenant	$ 7
Minimum liquidity	5
Maximum aggregate amount of earn-out payments during Relief Period	$ 7
Federal Funds Effective Swap Rate | Third Amendment [Member] | Debt Interest Period Three [Member]
Debt Instrument [Line Items]
Spread on floating interest rate (as a percent)	0.50%
Minimum | Revolving Credit Facility | Debt Interest Period Four [Member]
Debt Instrument [Line Items]
Commitment fee (as a percent)	0.15%
Minimum | Letters of Credit
Debt Instrument [Line Items]
Commitment fee (as a percent)	0.84%
Minimum | Letters of Credit | Debt Interest Period Four [Member]
Debt Instrument [Line Items]
Commitment fee (as a percent)	0.84%
Minimum | Base rate | Third Amendment [Member] | Debt Interest Period Four [Member]
Debt Instrument [Line Items]
Spread on floating interest rate (as a percent)	0.125%
Maximum | Revolving Credit Facility | Debt Interest Period Four [Member]
Debt Instrument [Line Items]
Commitment fee (as a percent)	0.35%
Maximum | Letters of Credit
Debt Instrument [Line Items]
Commitment fee (as a percent)	2.50%
Maximum | Letters of Credit | Debt Interest Period Four [Member]
Debt Instrument [Line Items]
Commitment fee (as a percent)	2.00%
Maximum | Base rate | Third Amendment [Member] | Debt Interest Period Four [Member]
Debt Instrument [Line Items]
Spread on floating interest rate (as a percent)	1.00%

DEBT OBLIGATIONS - Principal in

DEBT OBLIGATIONS - Principal installments (Details) - USD ($) $ in Thousands	Jan. 01, 2021	Dec. 27, 2019
DEBT OBLIGATIONS
2021	$ 14,996
2022	13,000
2023	13,000
2024	73,000
Total debt obligations	113,996	$ 131,060
Issuance costs and debt discounts	(822)	(709)
Long-term Debt	$ 113,174	$ 130,351

GOODWILL AND OTHER INTANGIBLE_3

GOODWILL AND OTHER INTANGIBLE ASSETS - Carrying Value of Goodwill by Reporting Unit (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 01, 2021	Dec. 27, 2019
Changes in carrying value of goodwill
Goodwill at beginning of period	$ 127,647	$ 97,748
Additional Purchase Cost		39,690
Additions/Adjustments	2,477	(9,791)
Goodwill at end of period	130,124	127,647
Goodwill	127,647	97,748
Energy
Changes in carrying value of goodwill
Goodwill at beginning of period	126,898	96,999
Additional Purchase Cost		39,690
Additions/Adjustments	2,477	(9,791)
Goodwill at end of period	129,375	126,898
Goodwill	129,375	96,999
Engineering and Consulting
Changes in carrying value of goodwill
Goodwill at beginning of period	749	749
Goodwill at end of period	749	749
Goodwill	$ 749	$ 749

GOODWILL AND OTHER INTANGIBLE_4

GOODWILL AND OTHER INTANGIBLE ASSETS - Gross Amount and Amortization (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 01, 2021	Dec. 27, 2019	Dec. 28, 2018
Goodwill and other intangible assets
Gross Amount	$ 98,924	$ 98,158
Gross Amount of Intangible Assets	99,234	98,158
Accumulated Amortization	34,978	21,321
Amortization expense for acquired identifiable intangible assets	13,700	11,600	$ 4,500
Estimated amortization expense for acquired identifiable intangible assets
2021	11,543
2022	11,227
2023	9,928
2024	6,806
2025	6,235
Thereafter	18,517
Total estimated amortization expense	64,256
Goodwill impairment
Goodwill impairment	0	0	$ 0
Backlog
Goodwill and other intangible assets
Gross Amount	7,944	7,134
Accumulated Amortization	$ 6,249	3,763
Amortization Period (in years)	1 year
Tradename
Goodwill and other intangible assets
Gross Amount	$ 15,911	13,351
Accumulated Amortization	$ 6,984	4,882
Tradename | Minimum
Goodwill and other intangible assets
Amortization Period (in years)	2 years 6 months
Tradename | Maximum
Goodwill and other intangible assets
Amortization Period (in years)	6 years
Non-compete agreements
Goodwill and other intangible assets
Gross Amount	$ 1,420	2,320
Accumulated Amortization	$ 1,390	1,384
Non-compete agreements | Minimum
Goodwill and other intangible assets
Amortization Period (in years)	4 years
Non-compete agreements | Maximum
Goodwill and other intangible assets
Amortization Period (in years)	5 years
Developed technology
Goodwill and other intangible assets
Gross Amount	$ 15,500	14,620
Accumulated Amortization	$ 6,107	3,227
Amortization Period (in years)	8 years
In-process research and technology
Goodwill and other intangible assets
Gross Amount of Indefinite Lived Intangible Assets	$ 310
Customer relationships
Goodwill and other intangible assets
Gross Amount	58,149	60,733
Accumulated Amortization	$ 14,248	$ 8,065
Customer relationships | Minimum
Goodwill and other intangible assets
Amortization Period (in years)	5 years
Customer relationships | Maximum
Goodwill and other intangible assets
Amortization Period (in years)	8 years

LEASES - Narrative (Details)

LEASES - Narrative (Details)	12 Months Ended
	Jan. 01, 2021
LEASES
Lease practical expedients package	true
Lease practical expedients use of hindsight	false

LEASES - Change in accounting p

LEASES - Change in accounting policy (Details) $ in Thousands	12 Months Ended
	Jan. 01, 2021USD ($)
Leases
Operating lease, option to extend	true
Operating lease, option to terminate	true
Residual value guarantee	$ 0
Minimum
Leases
Operating lease, remaining lease term	1 year
Maximum
Leases
Operating lease, remaining lease term	8 years
Operating lease, extension term	5 years
Operating lease, terminate term	1 year

LEASES - Lease expense (Details

LEASES - Lease expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 01, 2021	Dec. 27, 2019
Lease cost
Operating lease cost	$ 7,031	$ 5,053
Amortization of assets	589	509
Interest on lease liabilities	29	36
Total net lease cost	$ 7,649	$ 5,598

LEASES - Impact of Adoption (De

LEASES - Impact of Adoption (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 01, 2021	Dec. 27, 2019	Dec. 28, 2018
Operating leases:
Right-of-use assets	$ 20,130	$ 22,297
Lease liability	$ 5,844	$ 5,550
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Lease liability	Lease liability
Lease liability, less current portion	$ 15,649	$ 18,411
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Lease liability, less current portion	Lease liability, less current portion
Total lease obligations	$ 21,493	$ 23,961
Operating Lease, Liability, Statement of Financial Position [Extensible List]	Total lease obligations	Total lease obligations
Finance leases (included in equipment and leasehold improvements, net):
Equipment and leasehold improvements, net	$ 30,715	$ 27,334
Accumulated depreciation and amortization	(18,209)	(15,283)
Total equipment and leasehold improvements, net	12,506	12,051
Finance lease obligations	248	375
Finance lease obligations, less current portion	236	191
Total lease obligations	$ 484	$ 566
Operating Leases	4 years 4 months 24 days	4 years 7 months 2 days
Finance Leases	2 years 7 days	1 year 5 months 19 days
Operating Leases, discount rate	4.44%	5.14%
Finance Leases, discount rate	3.74%	4.80%
Operating lease, rent expense	$ 7,600	$ 6,200
Operating leases rent expense, net			$ 4,500
Equipment under finance lease
Finance leases (included in equipment and leasehold improvements, net):
Equipment and leasehold improvements, net	2,370	1,957
Accumulated depreciation and amortization	(1,826)	(1,291)
Total equipment and leasehold improvements, net	$ 544	$ 666

LEASES - Supplemental cash flow

LEASES - Supplemental cash flow information (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 01, 2021	Dec. 27, 2019	Dec. 28, 2018
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flow from operating leases	$ 6,972	$ 5,151
Operating cash flow from finance leases	29	36
Financing cash flow from finance leases	549	639	$ 367
Right-of-use assets obtained in exchange for lease liabilities for operating leases	$ 3,186	$ 4,918

LEASES - Maturities of lease li

LEASES - Maturities of lease liabilities (Details) - USD ($) $ in Thousands	Jan. 01, 2021	Dec. 27, 2019
Operating
2021	$ 6,645
2022	5,818
2023	3,983
2024	2,611
2025	2,088
2026 and thereafter	2,489
Total lease payments	23,634
Less: Imputed interest	(2,141)
Total lease obligations	21,493	$ 23,961
Less: Current obligations	5,844	5,550
Noncurrent lease obligations	15,649	18,411
Finance
2021	261
2022	172
2023	54
2024	14
2025	2
Total lease payments	503
Less: Imputed interest	(19)
Total lease obligations	484	566
Finance lease obligations	248	375
Finance lease obligations, less current portion	$ 236	$ 191

COMMITMENTS AND VARIABLE INTE_2

COMMITMENTS AND VARIABLE INTEREST ENTITIES - Employee Benefit Plans (Details) $ in Millions	12 Months Ended
	Jan. 01, 2021USD ($)item	Dec. 27, 2019USD ($)	Dec. 28, 2018USD ($)
COMMITMENTS AND VARIABLE INTEREST ENTITIES
Number of VIE | item	1
Employee Benefit Plans
Maximum employee contribution as a percentage of compensation under 401 (k) Plan	50.00%
Service period (in months)	3 months
Attained age (in years)	21 years
Defined Contribution Plan, Employer Matching Contribution, Percent of Match	50.00%
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay	6.00%
Employer matching contributions | $	$ 1.5	$ 2	$ 1.1

SEGMENT AND GEOGRAPHICAL INFO_3

SEGMENT AND GEOGRAPHICAL INFORMATION (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Jan. 01, 2021USD ($)	Oct. 02, 2020USD ($)	Jul. 03, 2020USD ($)	Apr. 03, 2020USD ($)	Dec. 27, 2019USD ($)	Sep. 27, 2019USD ($)	Jun. 28, 2019USD ($)	Mar. 29, 2019USD ($)	Jan. 01, 2021USD ($)segment	Dec. 27, 2019USD ($)	Dec. 28, 2018USD ($)
SEGMENT INFORMATION
Number of reporting segments | segment									2
Segment reconciliation
Contract revenue	$ 96,897	$ 104,508	$ 83,549	$ 106,026	$ 129,416	$ 117,494	$ 104,396	$ 91,793	$ 390,980	$ 443,099	$ 272,252
Depreciation and amortization									18,743	15,027	6,060
Interest expense									5,068	4,900	700
Segment profit (loss) before income tax expense									(19,669)	4,656	12,161
Income tax (benefit) expense	(1,892)	(1,586)	(90)	(1,605)	1,188	(376)	(70)	(927)	(5,173)	(185)	2,131
Net income (loss)	(3,997)	$ 2,640	$ (4,985)	$ (8,154)	3,202	$ 416	$ 1,640	$ (417)	(14,496)	4,841	10,030
Segment assets(1)	410,323				439,913				410,323	439,913	300,911
Energy
Segment reconciliation
Contract revenue									324,178	370,715	196,833
Engineering and Consulting
Segment reconciliation
Contract revenue									66,802	72,384	75,419
Reporting Segments | Energy
Segment reconciliation
Contract revenue									324,178	370,715	196,833
Depreciation and amortization									17,666	13,703	5,274
Interest expense									32	32	312
Segment profit (loss) before income tax expense									(9,963)	11,971	8,959
Income tax (benefit) expense									(2,621)	3,308	1,570
Net income (loss)									(7,343)	8,664	7,390
Segment assets(1)	337,739				392,362				337,739	392,362	252,124
Reporting Segments | Engineering and Consulting
Segment reconciliation
Contract revenue									66,802	72,384	75,419
Depreciation and amortization									1,077	1,324	786
Interest expense											388
Segment profit (loss) before income tax expense									9,500	8,839	7,589
Income tax (benefit) expense									2,499	2,442	1,330
Net income (loss)									7,002	6,397	6,259
Segment assets(1)	21,796				23,682				21,796	23,682	20,402
Unallocated Corporate
Segment reconciliation
Interest expense									5,036	4,868
Segment profit (loss) before income tax expense									(19,206)	(16,154)	(4,387)
Income tax (benefit) expense									(5,051)	(5,935)	(769)
Net income (loss)									(14,155)	(10,220)	(3,619)
Segment assets(1)	73,918				46,999				73,918	46,999	51,515
Intersegment
Segment reconciliation
Contract revenue									0
Segment assets(1)	$ (23,130)				$ (23,130)				$ (23,130)	$ (23,130)	$ (23,130)

SEGMENT AND GEOGRAPHICAL INFO_4

SEGMENT AND GEOGRAPHICAL INFORMATION - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Jan. 01, 2021	Oct. 02, 2020	Jul. 03, 2020	Apr. 03, 2020	Dec. 27, 2019	Sep. 27, 2019	Jun. 28, 2019	Mar. 29, 2019	Jan. 01, 2021	Dec. 27, 2019	Dec. 28, 2018
Disaggregation of Revenue [Line Items]
Revenue	$ 96,897	$ 104,508	$ 83,549	$ 106,026	$ 129,416	$ 117,494	$ 104,396	$ 91,793	$ 390,980	$ 443,099	$ 272,252
Domestic
Disaggregation of Revenue [Line Items]
Revenue									390,980	443,099	272,252
Energy
Disaggregation of Revenue [Line Items]
Revenue									324,178	370,715	196,833
Energy | Domestic
Disaggregation of Revenue [Line Items]
Revenue									324,178	370,715	196,833
Engineering and Consulting
Disaggregation of Revenue [Line Items]
Revenue									66,802	72,384	75,419
Engineering and Consulting | Domestic
Disaggregation of Revenue [Line Items]
Revenue									66,802	72,384	75,419
Commercial
Disaggregation of Revenue [Line Items]
Revenue									41,367	44,206	25,597
Commercial | Energy
Disaggregation of Revenue [Line Items]
Revenue									36,212	39,311	20,715
Commercial | Engineering and Consulting
Disaggregation of Revenue [Line Items]
Revenue									5,155	4,895	4,882
Government
Disaggregation of Revenue [Line Items]
Revenue									155,233	124,069	132,988
Government | Energy
Disaggregation of Revenue [Line Items]
Revenue									93,821	57,020	62,897
Government | Engineering and Consulting
Disaggregation of Revenue [Line Items]
Revenue									61,412	67,049	70,091
Utilities
Disaggregation of Revenue [Line Items]
Revenue									194,380	274,824	113,667
Utilities | Energy
Disaggregation of Revenue [Line Items]
Revenue									194,145	274,384	113,221
Utilities | Engineering and Consulting
Disaggregation of Revenue [Line Items]
Revenue									235	440	446
Time-and-materials
Disaggregation of Revenue [Line Items]
Revenue									101,752	73,185	73,534
Time-and-materials | Energy
Disaggregation of Revenue [Line Items]
Revenue									47,912	18,625	13,790
Time-and-materials | Engineering and Consulting
Disaggregation of Revenue [Line Items]
Revenue									53,840	54,560	59,744
Unit-based
Disaggregation of Revenue [Line Items]
Revenue									180,186	287,369	127,049
Unit-based | Energy
Disaggregation of Revenue [Line Items]
Revenue									170,991	272,978	113,749
Unit-based | Engineering and Consulting
Disaggregation of Revenue [Line Items]
Revenue									9,195	14,391	13,300
Fixed price
Disaggregation of Revenue [Line Items]
Revenue									109,042	82,545	71,669
Fixed price | Energy
Disaggregation of Revenue [Line Items]
Revenue									105,275	79,112	69,294
Fixed price | Engineering and Consulting
Disaggregation of Revenue [Line Items]
Revenue									$ 3,767	$ 3,433	$ 2,375

SEGMENT AND GEOGRAPHICAL INFO_5

SEGMENT AND GEOGRAPHICAL INFORMATION - Concentration risk (Details) - Customer Concentration Risk - Revenue from Contract with Customer Benchmark - customer	12 Months Ended
	Jan. 01, 2021	Dec. 27, 2019	Dec. 28, 2018
CALIFORNIA
Concentration Risk [Line Items]
Customer concentration risk percentage	37.00%	41.10%	35.00%
NEW YORK
Concentration Risk [Line Items]
Customer concentration risk percentage	19.20%	27.20%	29.00%
Energy Segment
Concentration Risk [Line Items]
Number of customers	2
Top Ten Customers
Concentration Risk [Line Items]
Number of customers	10	10	10
Customer concentration risk percentage	48.00%	50.60%	56.90%
Los Angeles Department Of Water And Power
Concentration Risk [Line Items]
Number of customers	1
Customer concentration risk percentage	10.20%
Los Angeles Department of Water and Power And The Dormitory Authority State Of New York [[Member] | Energy Segment
Concentration Risk [Line Items]
Customer concentration risk percentage	22.50%
City Of Elk Grove [Member] | Engineering And Consulting Segment
Concentration Risk [Line Items]
Number of customers	1	1
Customer concentration risk percentage	18.20%	25.00%
Consolidated Edison Of New York And The Los Angeles Department Of Water And Power [Member]
Concentration Risk [Line Items]
Number of customers		2
Customer concentration risk percentage		29.10%
Consolidated Edison Of New York And The Los Angeles Department Of Water And Power [Member] | Energy Segment
Concentration Risk [Line Items]
Number of customers		2
Customer concentration risk percentage		34.70%
Consolidated Edison Of New York [Member]
Concentration Risk [Line Items]
Number of customers			1
Customer concentration risk percentage			19.00%
Consolidated Edison Of New York [Member] | Energy Segment
Concentration Risk [Line Items]
Number of customers			1
Customer concentration risk percentage			18.50%
City Of Elk Grove City Of Long Beach And Ygrene | Engineering And Consulting Segment
Concentration Risk [Line Items]
Number of customers			3
Customer concentration risk percentage			10.00%

SEGMENT AND GEOGRAPHICAL INFO_6

SEGMENT AND GEOGRAPHICAL INFORMATION - Unallocated Corporate Assets (Details) - USD ($) $ in Thousands	Jan. 01, 2021	Dec. 27, 2019	Dec. 28, 2018
Assets:
Cash and cash equivalents	$ 28,405	$ 5,452
Accounts receivable, net	60,403	57,504
Prepaid expenses	5,564	6,254
Goodwill	130,124	127,647	$ 97,748
Other receivables	6,405	4,845
Equipment and leasehold improvements, net	12,506	12,051
Right-of-use assets	20,130	22,297
Other	5,993	16,296
Deferred income taxes	14,111	9,312
Unallocated Corporate
Assets:
Cash and cash equivalents	28,405	5,452
Accounts receivable, net	(4,845)	(108)
Prepaid expenses	2,422	1,912
Intercompany receivables	691,440	125,126
Goodwill	2	2
Other receivables	4,409	3,915
Equipment and leasehold improvements, net	1,585	1,637
Investments in subsidiaries	26,576	23,130
Right-of-use assets	809	1,141
Other	444	606
Deferred income taxes	14,111	9,312
Total assets	$ 765,358	$ 172,125

SHAREHOLDERS' EQUITY (Details)

SHAREHOLDERS' EQUITY (Details) $ in Millions	Jan. 01, 2021shares	Dec. 27, 2019shares	Mar. 28, 2008shares	Mar. 01, 2008shares	Jun. 30, 2006shares	Jan. 02, 2009shares	Jun. 27, 2008shares	Jan. 01, 2021USD ($)planshares	Dec. 27, 2019USD ($)shares	Dec. 28, 2018USD ($)shares	Dec. 29, 2017shares	Dec. 30, 2016shares	Jan. 01, 2016shares	Dec. 28, 2012shares	Dec. 31, 2010shares	Jun. 08, 2017shares	Jun. 30, 2008shares	Mar. 31, 2008shares	Dec. 28, 2007shares
Equity plans
Number of share-based compensation plans | plan								2
2006 Plan
Equity plans
Granted (in shares)								0
Number of shares of common stock reserved for issuance					300,000
2008 Plan
Equity plans
Number of shares of common stock reserved for issuance	161,000							161,000										450,000
Shares available for grant under 2008 Plan from 2006 Plan																	70,333
Number of additional shares authorized									955,000		875,000	500,000		500,000	350,000
Amended And Restated 2006 Employee Stock Purchase Plan ESPP [Member]
Equity plans
Number of shares of common stock reserved for issuance	519,000							519,000								1,125,000			300,000
Number of additional shares authorized											825,000
Stock options
Equity plans
Compensation expense recognized | $								$ 16.7	$ 12.1	$ 6.3
Granted (in shares)								0		158,000
Options outstanding (in shares)	1,003,000	1,124,000						1,003,000	1,124,000	1,252,000	1,207,000
Stock options | 2006 Plan
Equity plans
Options outstanding (in shares)	0							0
Stock options | 2008 Plan
Equity plans
Maximum number of shares a participant may be granted in options to purchase during fiscal year								300,000
Incentive stock options | 2008 Plan
Equity plans
Outstanding options granted, net of forfeitures, expirations and exercises (in shares)			65,000	65,000		65,000	65,000	65,000	65,000	65,000	65,000	65,000	65,000	65,000	65,000
Non-statutory/Nonqualified stock options | 2006 Plan | Maximum
Equity plans
Expiration period from date of grant					10 years
Non-statutory/Nonqualified stock options | 2008 Plan
Equity plans
Outstanding options granted, net of forfeitures, expirations and exercises (in shares)	938,000	938,000		938,000
Non-statutory/Nonqualified stock options | 2008 Plan | Maximum
Equity plans
Expiration period from date of grant								10 years
Restricted stock | 2008 Plan
Equity plans
Shares granted	128,000	128,000		128,000
Performance Shares | 2008 Plan
Equity plans
Shares granted	380,000	380,000		380,000

SHAREHOLDERS' EQUITY - Stock Pu

SHAREHOLDERS' EQUITY - Stock Purchase Plan (Details) - shares	12 Months Ended
	Jan. 01, 2021	Dec. 27, 2019	Dec. 29, 2017	Dec. 30, 2016	Dec. 28, 2012	Dec. 31, 2010	Jun. 08, 2017	Mar. 31, 2008	Dec. 28, 2007	Jun. 30, 2006
2006 Plan
Employee Stock Purchase Plan
Number of shares of common stock reserved for issuance										300,000
2008 Plan
Employee Stock Purchase Plan
Number of shares of common stock reserved for issuance	161,000							450,000
Number of additional shares authorized		955,000	875,000	500,000	500,000	350,000
Amended And Restated 2006 Employee Stock Purchase Plan ESPP [Member]
Employee Stock Purchase Plan
Number of shares of common stock reserved for issuance	519,000						1,125,000		300,000
Number of additional shares authorized			825,000
Purchase price per share as a percentage of fair market value	85.00%
Amended And Restated 2006 Employee Stock Purchase Plan ESPP [Member] | Minimum
Employee Stock Purchase Plan
Percentage of participant's earnings to be contributed under a share based compensation plan	1.00%
Amended And Restated 2006 Employee Stock Purchase Plan ESPP [Member] | Maximum
Employee Stock Purchase Plan
Percentage of participant's earnings to be contributed under a share based compensation plan	10.00%

SHAREHOLDERS' EQUITY - Option A

SHAREHOLDERS' EQUITY - Option Activity (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Jan. 01, 2021	Dec. 27, 2019	Dec. 28, 2018	Dec. 30, 2016
Fully-vested options
Intrinsic value of the fully-vested options (in dollars)	$ 22.9
Stock price at the end of the year (in dollars per share)	$ 41.70
Stock options
Options
Outstanding (in shares)	1,124,000	1,252,000	1,207,000
Granted (in shares)	0		158,000
Exercised (in shares)	(119,000)	(115,000)	(85,000)
Forfeited or expired (in shares)	(2,000)	(13,000)	(28,000)
Outstanding (in shares)	1,003,000	1,124,000	1,252,000
Vested and expected to vest (in shares)	1,003,000	1,124,000	1,252,000
Exercisable (in shares)	952,000	958,000	838,000
Weighted-Average Exercise Price
Outstanding (in dollars per share)	$ 17.80	$ 16.87	$ 14.04
Granted (in dollars per share)			31.54
Exercised (in dollars per share)	9.12	8.08	7.85
Forfeited or expired	2.71	14.97	5.07
Outstanding (in dollars per share)	18.86	17.80	16.87
Vested (in dollars per share)	18.86	17.80	16.87
Exercisable (in dollars per share)	$ 18.16	$ 15.48	$ 12.20
Weighted-Average Remaining Contractual Term
Outstanding	5 years 5 months 4 days	6 years 21 days	6 years 7 months 13 days	7 years 7 days
Vested	5 years 5 months 4 days	6 years 21 days	6 years 7 months 13 days
Exercisable	5 years 3 months 21 days	5 years 8 months 4 days	5 years 6 months 29 days

SHAREHOLDERS' EQUITY - Nonveste

SHAREHOLDERS' EQUITY - Nonvested Option Activity (Details) - Stock options - $ / shares	12 Months Ended
	Jan. 01, 2021	Dec. 27, 2019	Dec. 28, 2018
Nonvested Options
Nonvested outstanding (in shares)	166,000	414,000	547,000
Granted (in shares)	0		158,000
Vested (in shares)	(114,000)	(242,000)	(263,000)
Forfeited (in shares)		(6,000)	(28,000)
Nonvested outstanding (in shares)	52,000	166,000	414,000
Nonvested Options, Weighted Average Grant-Date Fair Value
Nonvested (in dollars per share)	$ 12.15	$ 8.69	$ 6.43
Granted (in dollars per share)			12.73
Vested (in dollars per share)	30.97	9.43	7.29
Forfeited (in dollars per share)		10.87	5.07
Nonvested (in dollars per share)	$ 31.73	$ 12.15	$ 8.69

SHAREHOLDERS' EQUITY - Restrict

SHAREHOLDERS' EQUITY - Restricted Stock Activity (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Jan. 01, 2021	Dec. 27, 2019	Dec. 28, 2018
2008 Plan
Weighted-Average Grant Date Fair Value
Outstanding (in dollars per share)	$ 20.68	$ 21.94
Awarded (in dollars per share)	29.22	28.99	$ 21.94
Vested (in dollars per share)	28.26	38.20
Forfeited (in dollars per share)	28.62	27.28
Outstanding (in dollars per share)	$ 20.68	$ 20.68	$ 21.94
Stock options
Unrecognized compensation expense
Unrecognized compensation expense related to non-vested stock options (in dollars)	$ 0.4	$ 1.5	$ 3.6
Awards granted that were immediately vested (in shares)	0	0	0
Restricted stock
Unrecognized compensation expense
Unrecognized compensation expense related to non-vested stock other than options (in dollars)	$ 3.6	$ 1.5	$ 1
Restricted stock | 2008 Plan
Restricted Stock
Outstanding (in shares)	58,000	64,000	87,000
Awarded (in shares)	99,000	37,000	22,000
Vested (in shares)	(29,000)	(43,000)	(45,000)
Outstanding (in shares)	128,000	58,000	64,000
Weighted-Average Grant Date Fair Value
Outstanding (in dollars per share)	$ 33.33	$ 22.28	$ 17.67
Awarded (in dollars per share)	32.89	35.60	28.17
Vested (in dollars per share)	32.35	18.90	16.09
Outstanding (in dollars per share)	$ 33.21	$ 33.33	$ 22.28
Performance Shares
Unrecognized compensation expense
Unrecognized compensation expense related to non-vested stock other than options (in dollars)	$ 13.2	$ 21.5	$ 12.3
Weighted-average period over which unrecognized expense is expected to be recognized	7 months 9 days	7 months 9 days	7 months 9 days
Performance Shares | 2008 Plan
Restricted Stock
Outstanding (in shares)	431,000	280,000
Awarded (in shares)	413,000	329,000	280,000
Vested (in shares)	(447,000)	(175,000)
Forfeited (in shares)	(18,000)	(3,000)
Outstanding (in shares)	379,000	431,000	280,000

SHAREHOLDERS' EQUITY - Assumpti

SHAREHOLDERS' EQUITY - Assumptions (Details) - $ / shares	12 Months Ended				24 Months Ended
	Jan. 01, 2021	Dec. 27, 2019	Dec. 28, 2018	Dec. 29, 2017	Dec. 27, 2019
Amended And Restated 2006 Employee Stock Purchase Plan ESPP [Member]
Assumptions
Expected volatility (as a percent)	30.30%	35.60%
Expected volatility, maximum (as a percent)			37.90%
Expected dividends (as a percent)	0.00%	0.00%	0.00%
Expected term (in years)	6 months	6 months		6 months
Risk-free rate (as a percent)	0.90%	2.30%
Risk-free rate, maximum (as a percent)			1.40%
Fair value (in dollars per share)	$ 28.39	$ 33.01	$ 26.86
Stock options
Assumptions
Expected volatility (as a percent)	34.00%
Expected volatility, minimum (as a percent)		37.00%
Expected volatility, maximum (as a percent)		38.00%
Expected dividends (as a percent)	0.00%	0.00%
Expected term (in years)	6 years	6 years
Risk-free rate (as a percent)	2.49%
Risk-free rate, minimum (as a percent)		2.65%
Risk-free rate, maximum (as a percent)		2.78%
Granted (in shares)	0		158,000
Fair value (in dollars per share)			$ 12.73
Restricted stock | 2008 Plan
Assumptions
Vesting period (in years)	3 years
Performance Shares | 2008 Plan
Assumptions
Growth percentage for threshold number of units vest	10.00%
Growth percentage for targeted number of units vest	20.00%
Performance Shares | 2008 Plan | EBITDA Units
Assumptions
Vesting period (in years)	2 years				4 years
Vesting percentage	50.00%	50.00%
Performance Shares | 2008 Plan | EPS Units
Assumptions
Vesting percentage	50.00%	50.00%
Performance Shares | 2008 Plan | Minimum | EBITDA Units
Assumptions
Vesting period (in years)	2 years
Performance Shares | 2008 Plan | Maximum | EBITDA Units
Assumptions
Vesting period (in years)	4 years

INCOME TAXES (Details)

INCOME TAXES (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Jan. 01, 2021	Oct. 02, 2020	Jul. 03, 2020	Apr. 03, 2020	Dec. 27, 2019	Sep. 27, 2019	Jun. 28, 2019	Mar. 29, 2019	Jan. 01, 2021	Dec. 27, 2019	Dec. 28, 2018
Provision for income taxes
Current federal taxes									$ (592)	$ (548)	$ 3,632
Current state taxes									166	551	1,389
Current foreign taxes									18
Deferred federal taxes									(2,939)	(159)	(2,539)
Deferred state taxes									(1,826)	(29)	(351)
Total provision for income taxes	$ (1,892)	$ (1,586)	$ (90)	$ (1,605)	$ 1,188	$ (376)	$ (70)	$ (927)	$ (5,173)	$ (185)	$ 2,131

INCOME TAXES - Provision (Detai

INCOME TAXES - Provision (Details) - USD ($)	12 Months Ended
	Jan. 01, 2021	Dec. 27, 2019	Dec. 28, 2018
Income taxes
Valuation reserve related to California net operating losses	$ 86,000	$ 86,000
U.S. federal statutory rate (as a percent)	21.00%	21.00%	21.00%
Federal
Income taxes
Operating loss carryovers	$ 72,200,000
State
Income taxes
Operating loss carryovers	$ 59,200,000

INCOME TAXES - Sources (Details

INCOME TAXES - Sources (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Jan. 01, 2021	Oct. 02, 2020	Jul. 03, 2020	Apr. 03, 2020	Dec. 27, 2019	Sep. 27, 2019	Jun. 28, 2019	Mar. 29, 2019	Jan. 01, 2021	Dec. 27, 2019	Dec. 28, 2018
INCOME TAXES
U.S. federal statutory rate (as a percent)									21.00%	21.00%	21.00%
Sources and tax effects of the differences
Computed "expected" federal income tax expense									$ (4,130)	$ 977	$ 2,554
Permanent differences									122	163	77
Nondeductible Executive Compensation									1,386	688
Stock options and disqualifying dispositions									4	(731)	(354)
Energy efficient building deduction									(738)	(1,291)	(919)
Current and deferred state income tax expense, net of federal benefit									(1,205)	466	815
Federal deferred tax adjustments										231	220
Adjustment for uncertain tax positions									(142)	(282)	61
Research and development tax credit									(527)	(510)	(313)
Adjustment to prior earn-out liability											198
Non-deductible transaction expenses											203
Other									57	27	(15)
True up income tax accounts										77
Total provision for income taxes	$ (1,892)	$ (1,586)	$ (90)	$ (1,605)	$ 1,188	$ (376)	$ (70)	$ (927)	$ (5,173)	$ (185)	$ 2,131

INCOME TAXES - Deferred Tax (De

INCOME TAXES - Deferred Tax (Details) - USD ($) $ in Thousands	Jan. 01, 2021	Dec. 27, 2019
Deferred tax assets:
Accounts receivable allowance	$ 199	$ 315
Other accrued liabilities	1,676	2,124
Federal and state net operating losses	18,854	18,717
Lease Liability	5,856	6,467
Stock compensation	3,063	3,381
Adjustments to fair value of assets	56	79
Credit Carryforwards	496
Other	211	622
Total deferred tax assets	30,411	31,705
Valuation allowance	(86)	(86)
Net deferred tax assets	30,325	31,619
Deferred tax liabilities:
Deferred revenue	(2,999)	(5,031)
Fixed assets	(732)	(618)
Intangible assets	(6,796)	(10,077)
Lease Right Of Use Asset	(5,484)	(6,127)
Other	(203)	(454)
Deferred tax liability	(16,214)	(22,307)
Deferred Tax Assets, Net	$ 14,111	$ 9,312

INCOME TAXES - Uncertain tax be

INCOME TAXES - Uncertain tax benefits (Details) $ in Thousands	12 Months Ended
	Jan. 01, 2021USD ($)
Reconciliation of unrecognized tax benefits
Balance as of December 27, 2019	$ 142
Reductions for tax positions of prior years	$ (142)

EARNINGS PER SHARE (EPS) (Detai

EARNINGS PER SHARE (EPS) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Jan. 01, 2021	Oct. 02, 2020	Jul. 03, 2020	Apr. 03, 2020	Dec. 27, 2019	Sep. 27, 2019	Jun. 28, 2019	Mar. 29, 2019	Jan. 01, 2021	Dec. 27, 2019	Dec. 28, 2018
Earnings (Loss) per share:
Net income (loss)	$ (3,997)	$ 2,640	$ (4,985)	$ (8,154)	$ 3,202	$ 416	$ 1,640	$ (417)	$ (14,496)	$ 4,841	$ 10,030
Weighted-average common shares outstanding (in shares)	12,011,000	11,992,000	11,682,000	11,510,000	11,357,000	11,217,000	11,100,000	10,974,000	11,793,000	11,162,000	9,264,000
Effect of dilutive stock options and restricted stock awards (in shares)										604,000	499,000
Weighted-average common shares outstanding-diluted (in shares)	12,011,000	12,417,000	11,682,000	11,510,000	11,913,000	11,789,000	11,679,000	10,974,000	11,793,000	11,766,000	9,763,000
Earnings (Loss) per share:
Basic	$ (0.33)	$ 0.22	$ (0.43)	$ (0.71)	$ 0.28	$ 0.04	$ 0.15	$ (0.04)	$ (1.23)	$ 0.43	$ 1.08
Diluted	$ (0.33)	$ 0.21	$ (0.43)	$ (0.71)	$ 0.27	$ 0.04	$ 0.14	$ (0.04)	$ (1.23)	$ 0.41	$ 1.03
Stock options
Anti-dilutive securities excluded from the computation of earnings per share
Number of awards excluded from calculation of dilutive potential common shares (in shares)										155,300	247,800

BUSINESS COMBINATIONS (Acquisit

BUSINESS COMBINATIONS (Acquisitions) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	Oct. 28, 2019	Jul. 02, 2019	Mar. 08, 2019	Jan. 01, 2021	Oct. 02, 2020	Jul. 03, 2020	Apr. 03, 2020	Dec. 27, 2019	Sep. 27, 2019	Jun. 28, 2019	Mar. 29, 2019	Jan. 01, 2021	Dec. 27, 2019	Dec. 28, 2018	Jun. 26, 2019
Consideration for acquisitions
Period over which financial targets must be met												3 years
Cash paid													$ 71,756	$ 124,344
Allocation of acquired assets
Goodwill				$ 130,124				$ 127,647				$ 130,124	127,647	97,748
Additional amortization expense charge due to increase in fair value of intangible assets												13,700	11,600	4,500
Revenue and Income from operations
Revenues.				96,897	$ 104,508	$ 83,549	$ 106,026	129,416	$ 117,494	$ 104,396	$ 91,793	390,980	443,099	272,252
Income from operations				(5,718)	$ 1,601	$ (3,841)	$ (8,269)	$ 5,529	$ 1,295	$ 2,773	$ (234)	(16,227)	9,363	$ 12,771
Delayed Draw Term Loan Facility
Consideration for acquisitions
Maximum borrowing capacity															$ 50,000
E3, Inc.
Consideration for acquisitions
Tax deductible goodwill	$ 21,800
Number of trading days considered for calculation of weighted average price per share prior to closing date	10 days
Period over which financial targets must be met	3 years
Maximum Payout	$ 12,000
Cash paid	27,000
Other working capital adjustment	1,780
Issuance of common stock	5,000
Contingent consideration	6,000
Total consideration	39,780
Cash paid at closing	27,000
Allocation of acquired assets
Current assets	5,278
Non-current assets (1)	341
Cash	2,264
Equipment and leasehold improvements, net	409
Right-of-use asset	7,641
Current lease liability	(750)
Non-current lease liability	(6,890)
Liabilities	(4,325)
Goodwill	21,772
Net assets acquired	39,780
Increase in net carrying value of right of use assets, non-current lease liability, backlog, tradename, developed technology, and in-progress research and development				5,100								5,100
The decrease in the net carrying value of current assets, current lease liability, liabilities, customer relationships, non-compete, and goodwill.				4,500								4,500
Decrease in amortization expense due to a change in fair vaule of intangible assets												100
Revenue and Income from operations
Revenues.												23,200
Income from operations												4,300
E3, Inc. | Delayed Draw Term Loan Facility
Consideration for acquisitions
Proceeds from borrowings	30,000
E3, Inc. | Maximum
Consideration for acquisitions
Earn-Out Payments	12,000
Total consideration	44,000
E3, Inc. | Backlog
Allocation of acquired assets
Intangible assets	2,600
E3, Inc. | Customer relationships
Allocation of acquired assets
Intangible assets	6,050
E3, Inc. | Tradename
Allocation of acquired assets
Intangible assets	4,200
E3, Inc. | Developed technology
Allocation of acquired assets
Intangible assets	880
E3, Inc. | In-process research & development
Allocation of acquired assets
Intangible assets	$ 310
Onsite Energy Corporation
Consideration for acquisitions
Tax deductible goodwill		$ 8,600
Cash paid		24,905
Total consideration		24,905
Allocation of acquired assets
Current assets		19,058
Non-current assets (1)		10
Equipment and leasehold improvements, net		39
Right-of-use asset		828
Current lease liability		(168)
Non-current lease liability		(660)
Liabilities		(12,222)
Goodwill		8,600
Net assets acquired		24,905
Increase in the net carrying value of backlog, tradename and goodwill				3,500								3,500
Decrease in net carrying value of current assets and goodwill				$ 3,500								3,500
Decrease in amortization expense due to a change in fair vaule of intangible assets												700
Revenue and Income from operations
Revenues.												10,400
Income from operations												300
Onsite Energy Corporation | Backlog
Allocation of acquired assets
Intangible assets		1,510
Onsite Energy Corporation | Customer relationships
Allocation of acquired assets
Intangible assets		7,050
Onsite Energy Corporation | Tradename
Allocation of acquired assets
Intangible assets		860
The Weidt Group
Consideration for acquisitions
Tax deductible goodwill			$ 11,500
Cash paid			22,136
Total consideration			22,136
Allocation of acquired assets
Current assets			2,317
Non-current assets (1)			25
Equipment and leasehold improvements, net			198
Right-of-use asset			1,730
Current lease liability			(245)
Non-current lease liability			(1,533)
Liabilities			(612)
Goodwill			11,546
Net assets acquired			22,136
Revenue and Income from operations
Revenues.												14,900
Income from operations												1,900
The Weidt Group | Backlog
Allocation of acquired assets
Intangible assets			750
The Weidt Group | Customer relationships
Allocation of acquired assets
Intangible assets			4,240
The Weidt Group | Tradename
Allocation of acquired assets
Intangible assets			550
The Weidt Group | Developed technology
Allocation of acquired assets
Intangible assets			$ 3,170
Lime Energy
Unaudited pro forma financial information
Pro forma revenue												390,980	471,330
Pro forma income (loss) from operations												(16,227)	10,846
Pro forma net loss												$ (14,496)	$ (16,618)
Loss per share:
Basic (in dollars per share)												$ (1.23)	$ (1.49)
Diluted (in dollars per share)												$ (1.23)	$ (1.41)
Weighted average shares outstanding:
Basic (in shares)												11,793	11,162
Diluted (in shares)												11,793	11,766
Revenue and Income from operations
Revenues.												$ 48,400
Income from operations												$ 6,500
Willdan Energy Solutions | Onsite Energy Corporation | Maximum
Consideration for acquisitions
Total consideration		$ 26,400

QUARTERLY FINANCIAL INFORMATI_3

QUARTERLY FINANCIAL INFORMATION (UNAUDITED) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Jan. 01, 2021	Oct. 02, 2020	Jul. 03, 2020	Apr. 03, 2020	Dec. 27, 2019	Sep. 27, 2019	Jun. 28, 2019	Mar. 29, 2019	Jan. 01, 2021	Dec. 27, 2019	Dec. 28, 2018
QUARTERLY FINANCIAL INFORMATION (UNAUDITED)
Contract revenue	$ 96,897	$ 104,508	$ 83,549	$ 106,026	$ 129,416	$ 117,494	$ 104,396	$ 91,793	$ 390,980	$ 443,099	$ 272,252
Income (loss) from operations	(5,718)	1,601	(3,841)	(8,269)	5,529	1,295	2,773	(234)	(16,227)	9,363	12,771
Income tax expense (benefit)	(1,892)	(1,586)	(90)	(1,605)	1,188	(376)	(70)	(927)	(5,173)	(185)	2,131
Net income (loss)	$ (3,997)	$ 2,640	$ (4,985)	$ (8,154)	$ 3,202	$ 416	$ 1,640	$ (417)	$ (14,496)	$ 4,841	$ 10,030
Earnings (loss) per share:
Basic	$ (0.33)	$ 0.22	$ (0.43)	$ (0.71)	$ 0.28	$ 0.04	$ 0.15	$ (0.04)	$ (1.23)	$ 0.43	$ 1.08
Diluted	$ (0.33)	$ 0.21	$ (0.43)	$ (0.71)	$ 0.27	$ 0.04	$ 0.14	$ (0.04)	$ (1.23)	$ 0.41	$ 1.03
Weighted-average shares outstanding:
Basic	12,011	11,992	11,682	11,510	11,357	11,217	11,100	10,974	11,793	11,162	9,264
Diluted	12,011	12,417	11,682	11,510	11,913	11,789	11,679	10,974	11,793	11,766	9,763