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EXHIBIT 4.01


                 SECOND AMENDMENT AND WAIVER TO CREDIT AGREEMENT

Harris Trust and Savings Bank
Chicago, Illinois

Gentlemen:

         Reference is hereby made to that certain Credit Agreement (the "Credit
Agreement"), dated as of September 23, 1997, by and among Comshare, Incorporated
(the "Company") and Comshare Limited (the "Borrowing Subsidiary") (together the
"Borrowers") and Harris Trust and Savings Bank (the "Bank"). All capitalized
terms used herein without definition shall have the same meanings herein as such
terms have in the Credit Agreement.

         The Borrowers have requested that the Bank extend the Termination Date
of, waive the Company's past noncompliance with, and amend certain provisions
of, the Credit Agreement and the Bank will do so under the terms and conditions
set forth in this Amendment.

         1.       WAIVER.

         The Company has informed the Bank that, as of September 30, 1999, the
Company was not in compliance with Section 8.8 of the Credit Agreement. The Bank
hereby agrees to waive compliance with Section 8.8 of the Credit Agreement as of
September 30, 1999, provided that this waiver shall not become effective unless
and until the conditions precedent set forth in Section 3 hereof have been
satisfied.

          2.    AMENDMENTS.

                  (a) The definition of "Termination Date" appearing in Section
         5 of the Credit Agreement shall be amended and as so amended shall be
         restated to read as follows:

                  "Termination Date" means September 30, 2001, or such earlier
                  date on which the Commitment is terminated in whole pursuant
                  to Section 3.4, 9.2 or 9.3 hereof, or such later date to which
                  the Termination Date is extended pursuant to Section 12.4
                  hereof.

                  (b) "Sections 8.8 and 8.9 of the Credit Agreement shall be
         amended and restated in their entirety and so amended shall be restated
         to read as follows:

                           "Section 8.8.    Fixed  Charge  Coverage  Ratio.
                  The  Company  shall not,  as of each date set  forth  below
                  (commencing  on  September 30,  1998), permit the Fixed
                  Charge  Coverage  Ratio to be less than  indicated  below for
                  such period:


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                                                               FIXED CHARGE
                DURING THE PERIOD                             COVERAGE RATIO
                                                             FOR SUCH PERIOD
                                                              SHALL NOT BE
                                                               LESS THAN:

            The three calendar months       9/30/99              1.05 to 1
            ending

            The six calendar months         12/31/99             0.90 to 1
            ending

            The nine calendar months        3/31/00              1.05 to 1
            ending

            The twelve calendar months    6/30/00 and            1.25 to 1
            ending                       each calendar
                                            quarter
                                           thereafter

             Section 8.9. Minimum EBITDAL. The Company will earn
    an EBITDAL for each period set forth below in an amount not
    less than indicated below for such period:
                                                               EBITDAL FOR
                DURING THE PERIOD                              SUCH PERIOD
                                                              SHALL NOT BE
                                                                LESS THAN:

            The three calendar months       9/30/99             $1,500,000
            ending

            The six calendar months         12/31/99            $2,300,000
            ending

            The nine calendar months        3/31/00             $4,000,000
            ending

            The twelve calendar months      6/30/00             $6,300,000
            ending

            The three calendar months     9/30/00 and           $1,875,000"
            ending                       each calendar
                                            quarter
                                           thereafter

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          3.    CONDITIONS PRECEDENT.

         The effectiveness of this Amendment is subject to the satisfaction of
all of the following conditions precedent:

                  (a) The Borrowers and the Bank shall have executed and
         delivered this Amendment.

                  (b) The Guarantors and each party signatory to that certain
         Debt Subordination Agreement dated September 23, 1997 shall have each
         executed and delivered to the Bank their consent to this Amendment in
         the forms set forth below.

                  (c) Legal matters incident to the execution and delivery of
         this Amendment shall be satisfactory to the Bank and its counsel.

          4.    REPRESENTATIONS.

         In order to induce the Bank to execute and deliver this Amendment, the
Borrowers hereby represent to the Bank that as of the date hereof the
representations and warranties set forth in Section 6 of the Credit Agreement
are and shall be and remain true and correct (except that the representations
contained in Section 6.5 shall be deemed to refer to the most recent financial
statements of the Borrowers delivered to the Bank) and, except as waived herein,
the Borrowers are in compliance with the terms and conditions of the Credit
Agreement and no Default or Event of Default has occurred and is continuing
under the Credit Agreement or shall result after giving effect to this
Amendment.

          5.    MISCELLANEOUS.

                5.1. The Borrowers heretofore executed and delivered to the Bank
the Security Agreement, Pledge Agreement and certain other Collateral Documents.
The Borrowers hereby acknowledge and agree that the Liens created and provided
for by the Collateral Documents continue to secure, among other things, the
Obligations arising under the Credit Agreement as amended hereby; and the
Collateral Documents and the rights and remedies of the Bank thereunder, the
obligations of the Borrowers thereunder, and the Liens created and provided for
thereunder remain in full force and effect and shall not be affected, impaired
or discharged hereby. Nothing herein contained shall in any manner affect or
impair the priority of the liens and security interests created and provided for
by the Collateral Documents as to the indebtedness which would be secured
thereby prior to giving effect to this Amendment.

                5.2. Except as specifically amended herein, the Credit Agreement
shall continue in full force and effect in accordance with its original terms.
Reference to this specific Amendment need not be made in the Credit Agreement,
the Note, or any other instrument or document executed in connection therewith,
or in any certificate, letter or communication issued or made pursuant to or
with respect to the Credit Agreement, any reference in any of such items to the
Credit Agreement being sufficient to refer to the Credit Agreement as amended
hereby.


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                5.3. The Borrowers agree to pay on demand all costs and expenses
of or incurred by the Bank in connection with the negotiation, preparation,
execution and delivery of this Amendment, including the fees and expenses of
counsel for the Bank.

                5.4. This Amendment may be executed in any number of
counterparts, and by the different parties on different counterpart signature
pages, all of which taken together shall constitute one and the same agreement.
Any of the parties hereto may execute this Amendment by signing any such
counterpart and each of such counterparts shall for all purposes be deemed to be
an original. This Amendment shall be governed by the internal laws of the State
of Illinois.

                           [SIGNATURE PAGE TO FOLLOW]


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     Dated as of this 10th day of October, 1999.

                                       COMSHARE, INCORPORATED


                                       By:  /s/  Kathryn A. Jehle
                                          --------------------------------------
                                         Name: Kathryn. A. Jehle
                                              ----------------------------------
                                         Title: Senior Vice President and CFO
                                               ---------------------------------

                                       COMSHARE LIMITED


                                       By:: /s/  Kathryn A. Jehle
                                           -------------------------------------
                                          Name: Kathryn. A. Jehle
                                                --------------------------------
                                           Title: Director
                                                  ------------------------------


     Accepted and agreed to as of the date last above written.

                                       HARRIS TRUST AND SAVINGS BANK


                                       By: /s/  Kirby M. Law
                                          --------------------------------------
                                         Name: Kirby M. Law
                                              ----------------------------------
                                           Title: Vice President
                                                 -------------------------------

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                     GUARANTORS' ACKNOWLEDGEMENT AND CONSENT


         Each of the undersigned Guarantors heretofore executed and delivered to
the Bank a separate Guaranty Agreement each dated September 23, 1997. Each of
the undersigned hereby consent to the Second Amendment and Waiver to Credit
Agreement as set forth above and confirm that its Guaranty Agreement and all of
the undersigned's obligations thereunder remain in full force and effect. Each
of the undersigned further agree that the consent of the undersigned to any
further amendments to the Credit Agreement shall not be required as a result of
this consent having been obtained, except to the extent, if any, required by the
Guaranty Agreement referred to above.

                                       COMSHARE (U.S.), INC.
                                       COMSHARE LIMITED (CANADA)
                                       COMSHARE HOLDINGS COMPANY


                                       By: /s/  Kathryn A. Jehle
                                          --------------------------------------
                                         Name: Kathryn. A. Jehle
                                              ----------------------------------
                                         Title: Senior Vice President and CFO
                                               ---------------------------------

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               SUBORDINATED CREDITORS' ACKNOWLEDGEMENT AND CONSENT


         Each of the undersigned heretofore executed in favor of the Bank a Debt
Subordination Agreement dated September 23, 1997. Each of the undersigned hereby
consent to the Second Amendment and Waiver to Credit Agreement as set forth
above and confirms that the Debt Subordination Agreement and all of the
undersigned's obligations thereunder remain in full force and effect. Each of
the undersigned further agree that the consent of the undersigned to any further
amendments to the Credit Agreement shall not be required as a result of this
consent having been obtained, except to the extent, if any, required by the Debt
Subordination Agreement referred to above.

                                       COMSHARE, INCORPORATED
                                       COMSHARE (U.S.), INC.
                                       COMSHARE INTERNATIONAL B.V.
                                       COMSHARE LIMITED
                                       COMSHARE HOLDINGS COMPANY
                                       COMSHARE LIMITED


                                       By: /s/  Kathryn A. Jehle
                                          --------------------------------------
                                         Name: Kathryn. A. Jehle
                                              ----------------------------------
                                         Title: Senior Vice President and CFO
                                               ---------------------------------

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