EXHIBIT 32.1

    CERTIFICATION OF CHIEF EXECUTIVE OFFICER REQUIRED BY SECTION 1350 OF THE
    UNITED STATES CODE ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY
                                  ACT OF 2002

    I, Hamish N. Brewer, Chief Executive Officer of JDA Software Group, Inc.
    (the "Registrant"), do hereby certify in accordance with 18 U.S.C. 1350, as
    adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that,
    based on my knowledge:

            (1) the Quarterly Report on Form 10-Q of the Registrant, to which
            this certification is attached as an exhibit (the "Report"), fully
            complies with the requirements of section 13(a) of the Securities
            Exchange Act of 1934 (15 U.S.C. 78m); and

            (2) the information contained in the Report fairly presents, in all
            material respects, the financial condition and results of operations
            of the Registrant.

Dated: August 13, 2003                                   /s/ Hamish N. Brewer
                                                         --------------------
                                                         Hamish N. Brewer
                                                         Chief Executive Officer

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