<PAGE>   1

EXHIBIT 10a. SECOND AMENDMENT TO CONSULTING AGREEMENT BETWEEN THE COMPANY AND
                 LOUIS M. BROWN JR.


                    SECOND AMENDMENT TO CONSULTING AGREEMENT

         This Second Amendment to the Consulting Agreement is effective the 26TH
day of April, 2001 (the "Second Amendment"), by and between MICROS SYSTEMS,
INC., a Maryland corporation, with offices located at 7031 Columbia Gateway
Drive, Columbia, Maryland 21046-2289 (hereinafter referred to as the "Company"),
and Louis M. Brown, Jr., whose address is Louis M. Brown, Jr., 4801 Maury Lane,
Alexandria, VA 22304-1909 (hereinafter referred to as the "Consultant").

         WHEREAS, the Consultant and the Company entered into a Consulting
Agreement dated June 30, 1995, as amended by the First Amendment dated January
27, 1999 (the "Agreement"); and

         WHEREAS, the parties hereto would like to amend the Agreement pursuant
to this Second Amendment in an effort: (i) to assure the availability of
management with industry and management expertise; (ii) to solidify the
long-term management structure of the Company; and (iii) to establish a
management succession plan that is in the best interest of the Company.

         NOW, THEREFORE, the Company and the Consultant, for good and valuable
consideration, and pursuant to the terms, conditions, and covenants contained
herein, hereby agree as follows:

1.       Section 3 of the Agreement, captioned "Term", shall be deleted in its
entirety and the following new language inserted in lieu thereof:

         "The term of this Agreement shall commence upon the day and year first
         above written ("Commencement Date") and shall continue until June 30,
         2005, unless sooner terminated, as provided herein."

2.       Section 4 of the Agreement, captioned "Compensation", is amended by
deleting the compensation chart contained therein in its entirety and inserting
the following in lieu thereof:

<TABLE>
<CAPTION>
         ------------------------------------------------------------------------------
         Period                                                      Compensation
         ------------------------------------------------------------------------------
<S>                                                                  <C>
         July 1, 1995 through June 30, 1996                          $150,000
         ------------------------------------------------------------------------------
         July 1, 1996 through June 30, 1997                          $160,000
         ------------------------------------------------------------------------------
         July 1, 1997 through June 30, 1998                          $170,000
         ------------------------------------------------------------------------------
         July 1, 1998 through June 30, 1999                          $180,000
         ------------------------------------------------------------------------------
         July 1, 1999 through June 30, 2000                          $190,000
         ------------------------------------------------------------------------------
         July 1, 2000 through June 30, 2001                          $210,000
         ------------------------------------------------------------------------------
         July 1, 2001 through June 30, 2002                          $230,000
         ------------------------------------------------------------------------------
         July 1, 2002 through June 30, 2003                          $250,000
         ------------------------------------------------------------------------------
         July 1, 2003 through June 30, 2004                          $250,000
         ------------------------------------------------------------------------------
         July 1, 2004 through June 30, 2005                          $250,000
         ------------------------------------------------------------------------------
</TABLE>

<PAGE>   2

3.       Section 5 of the Agreement, captioned "Bonuses", is amended by deleting
the target bonus chart contained therein in its entirety, and inserting the
following in lieu thereof:

<TABLE>
<CAPTION>
         ------------------------------------------------------------------------------
          Fiscal Year Ending                                         Target Bonus
         ------------------------------------------------------------------------------
<S>                                                                  <C>
         June 30, 1996                                               $70,000
         ------------------------------------------------------------------------------
         June 30, 1997                                               $80,000
         ------------------------------------------------------------------------------
         June 30, 1998                                               $90,000
         ------------------------------------------------------------------------------
         June 30, 1999                                               $100,000
         ------------------------------------------------------------------------------
         June 30, 2000                                               $110,000
         ------------------------------------------------------------------------------
         June 30, 2001                                               $130,000
         ------------------------------------------------------------------------------
         June 30, 2002                                               $150,000
         ------------------------------------------------------------------------------
         June 30, 2003                                               $150,000
         ------------------------------------------------------------------------------
         June 30, 2004                                               $150,000
         ------------------------------------------------------------------------------
         June 30, 2005                                               $150,000
         ------------------------------------------------------------------------------
</TABLE>

4.       The first paragraph of Section 13(c)(3) of the Agreement shall be
deleted in its entirety and the following new language inserted in lieu thereof:

         "Payment Upon Termination By The Company. If the Company terminates
         this Agreement for any reason other than Good Cause, the Consultant
         shall be entitled to receive from the Company and the Company shall pay
         to the Consultant in one lump sum, within fifteen (15) days following
         the termination of this Agreement, all of the compensation and Target
         Bonus payments provided for in Sections 4 and 5 of this Agreement for
         the period beginning on the date of the termination of the Agreement
         and ending on June 30, 2005."

5.       The first paragraph of Section 13(c)(4) of the Agreement shall be
deleted in its entirety and the following new language inserted in lieu thereof:

         "Payment Upon Termination By The Consultant. If the Consultant
         terminates this Agreement for Good Reason, other than Good Reason
         described in Section 13(a)(3)a), he shall be entitled to receive from
         the Company and the Company shall pay to the Consultant in one lump
         sum, within fifteen (15) days following the date of the Consultant's
         termination of this Agreement, all of the compensation and Target Bonus
         payments provided for in Sections 4 and 5 of this Agreement for the
         period beginning on the date of the Consultant's termination of this
         Agreement and ending on June 30, 2005. If the Consultant terminates
         this Agreement for the Good Reason described in Section 13(a)(3)a),
         then and in such event, he shall be entitled to receive from the
         Company and the Company shall pay to the Consultant in one lump sum,
         within fifteen (15) days following the date of the Consultant's
         termination of this Agreement, an amount equal to the lesser of (i) all
         of the compensation and Target Bonus payments provided for in Sections
         4 and 5 of this Agreement for the period beginning on the date of the
         Consultant's termination and ending on June 30, 2005, or (ii) all of
         the compensation and Target Bonus payments provided for in Sections 4
         and 5 of this Agreement for the period commencing on the date of the
         Consultant's termination and ending on the third anniversary of the
         date of the Consultant's termination."

6.       All other provisions of the Agreement shall remain in full force and
effect.


         IN WITNESS WHEREOF, the parties have executed this Second Amendment as
of the dates indicated below, the effective date of this Second Amendment being
the 26TH day of April 2001.


<PAGE>   3


<TABLE>
<CAPTION>
                                        COMPANY:
                                        --------
ATTEST:                                 MICROS SYSTEMS, INC.
-------                                 --------------------
<S>                                     <C>                                             <C>
                                        By:                                              (SEAL)
------------------                      --------------------------------                 ------
                                        A. L. Giannopoulos
                                        ------------------
                                        President and Chief Executive Officer
                                        -------------------------------------
[Corporate Seal]
----------------
                                        CONSULTANT:
                                        -----------

WITNESS:
--------
                                                                                         (SEAL)
------------------                         --------------------------------              ------
                                                 Louis M. Brown, Jr.
                                           --------------------------------
</TABLE>