<PAGE>
                                                                   EXHIBIT 10.15
 
                              SEVERANCE AGREEMENT


          THIS SEVERANCE AGREEMENT ("Agreement") is made and entered into as of
the ____ day of __________, 199  by and between Sterling Software, Inc., a
Delaware corporation ("Sterling Software"), and ____________________, an
individual ("Executive").

                                 RECITALS:

     WHEREAS, Sterling Software acquires, develops, markets and supports a broad
range of products and services; and

     WHEREAS, Sterling Software desires to retain Executive as its
____________________; and

     WHEREAS, Executive is willing to accept such responsibilities;

     NOW, THEREFORE, in consideration of the premises and covenants contained
herein and other good and valuable consideration, the sufficiency of which is
hereby acknowledged, the parties hereto agree as follows:

                                 AGREEMENTS:

     1.   Employment.  Executive agrees to render such managerial services as
          ----------                                                         
          are customarily required of the ____________________, and Sterling
          Software agrees to utilize such services on the terms and conditions
          contained herein.

     2.   Term.  This Agreement shall commence on the date first set forth above
          ----                                                                  
          and shall continue in effect for _____ (__) months after the "Notice
          Date" as defined in Section 3 hereof.

     3.   Termination of Employment.  The parties acknowledge that Executive is
          -------------------------                                            
          employed "at will" and may be terminated by Sterling Software at any
          time with or without cause.  The Executive shall be entitled to
          termination pay calculated in accordance with Section 4 hereof upon
          termination of Executive's employment by Sterling Software, with or
          without cause.

          The date on which a notice of termination is given to Executive by
          Sterling Software shall be deemed the "Notice Date" with the
          termination to be effective _____ (__) months following the Notice
          Date.  On the Notice Date, Executive shall be deemed to have been
          assigned "no duties," shall vacate his or her office and shall resign
          as an officer of Sterling Software and its subsidiaries.  Since
          Executive will be assigned "no duties" with Sterling Software,
          Executive shall be free to pursue other employment or consulting
          opportunities during the _____ month period in which Executive
          receives termination pay.
<PAGE>
 
     4.   Termination Pay.  For purposes of this Agreement, if Executive's
          ---------------                                                 
          employment is terminated (or deemed to be terminated) pursuant to
          Section 3, upon receipt from Executive (or Executive's estate or
          personal representative) of a fully executed release in form
          reasonably acceptable to counsel for Sterling Software, Sterling
          Software shall pay, or cause one of its subsidiaries to pay, to
          Executive as termination pay:

          (a)  an amount equal to _____ hundred percent of Executive's aggregate
               monthly salary for the twelve (12) months immediately preceding
               the Notice Date (or, if Executive shall not have been employed
               for such twelve month period, an amount equal to _______ hundred
               percent of Executive's annual salary rate in effect immediately
               prior to the Notice Date); and

          (b)  an amount equivalent to the product of _____ times:

               (i)  if Executive shall have completed at least twelve months
                    employment with Sterling Software prior to the Notice Date,
                    the amount of Executive's aggregate bonuses during the
                    twelve months immediately prior to the Notice Date (the
                    "Last Bonus"), after deducting from such product one hundred
                    percent (100%) of the accrued but unpaid bonus amount
                    Executive is entitled to receive on the Notice Date,
                    pursuant to any bonus or incentive compensation plan of
                    Sterling Software, for periods of service after the period
                    for which Executive received or was entitled to receive the
                    Last Bonus or

               (ii) if Executive shall not have completed at least twelve months
                    employment with Sterling Software prior to the Notice Date,
                    an amount equal to the greater of

                    (x)  the amount of the Last Bonus, if any or

                    (y)  100% of the aggregate of the budgeted annual bonus,
                         incentive or other budgeted payments of cash
                         compensation, in addition to the Executive's annual
                         base salary, at plan for such Executive in effect
                         immediately prior to the Notice Date,

                    after deducting from such product under this clause (ii) one
                    hundred percent (100%) of the accrued but unpaid bonus
                    amount Executive is entitled to receive on the Notice Date,
                    pursuant to any bonus or incentive plan of Sterling
                    Software, for periods of service after the period for which
                    Executive received or was entitled to receive the Last
                    Bonus, if any.

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          In the event of Executive's death or disability following the Notice
          Date, Executive, Executive's estate or Executive's personal
          representative, as the case may be, shall continue to receive the
          termination payments provided for in this Section 4.

     5.   Disbursement of Termination Pay.  The aggregate amount of all
          -------------------------------                              
          termination payments that are payable to Executive as provided in
          Section 4 hereof shall be determined in good faith by Sterling
          Software within 15 days following the Notice Date, and such
          termination payments shall be distributed by Sterling Software to
          Executive in _____ (__) equal bi-monthly installments beginning thirty
          (30) days following the Notice Date and continuing bi-monthly
          thereafter.

     6.   Continuation of Medical and Health Benefits.  For a period of _____
          -------------------------------------------                        
          (__) months following the Notice Date, Sterling Software shall arrange
          to provide Executive, at no additional charge to Executive, with life,
          medical, dental, health, accident and disability insurance benefits
          substantially similar to those that Executive is receiving or is
          entitled to receive immediately prior to the Notice Date, which
          benefits shall in no event be less than those benefits in effect
          immediately prior to the Notice Date.

     7.   Continued Participation in Employee Plans.  For a period of _____ (__)
          -----------------------------------------                             
          months following the Notice Date, Executive shall continue to
          participate in Sterling Software's Employee Stock Ownership Plan
          and/or 401(k) Plan and any other such plans as may be adopted in the
          future for the benefit and retention of Sterling Software's executive
          officers.  In no event will Sterling Software be required to make any
          new grants of options to such Executive under Sterling Software's
          Stock Option Plans after the Notice Date.

     8.   Change-in-Control.  Sterling Software and the Executive are parties to
          -----------------                                                     
          a Change-in-Control Severance Agreement, dated as of ________ __, 199
          (as such agreement may be amended from time to time, the "Change-in-
          Control Agreement").  Notwithstanding anything contained in this
          Agreement to the contrary, in the event the Notice Date occurs under
          circumstances in which the Executive would otherwise be entitled to
          receive payments and benefits under both this Agreement and the
          Change-in-Control Agreement, the Executive shall have the right to
          elect to receive payments and benefits under either this Agreement or
          the Change-in-Control Agreement, but not both.  Within five business
          days following the Notice Date under circumstances in which this
          Section 8 would apply, Sterling Software shall provide the Executive,
          in writing, a reasonably detailed determination of the payments and
          other benefits under each of this Agreement and the Change-in-Control
          Agreement.  The Executive shall make the election provided for in this
          Section 8 within thirty calendar days after Executive's receipt of the
          written determination referred to in the preceding sentence; provided,
          however, that if such election is not so made within such 30-day
          period, 

                                      -3-
<PAGE>
 
          the Executive shall be irrevocably deemed to have elected to receive
          payments and benefits under the Change-in-Control Agreement. Prior to
          the date on which Executive makes or is deemed to have made the
          election referred to above, he shall receive all benefits under
          Sections 4, 5, 6 and 7 of this Agreement as if the Executive had made
          the election to receive benefits and payments under this Agreement.

     9.   Miscellaneous.
          ------------- 

          (i)  Notices, demands, payments, reports and correspondence shall be
               addressed to the parties hereto at the address for such party set
               forth below or such other places as may from time to time be
               designated in writing to the other party.  Notices hereunder
               shall be deemed to be given on the date such notices are actually
               received.

               If to Sterling Software, to:  8080 N. Central Expressway,
                                             Suite 1100
                                             Dallas, Texas 75206
                                             Attention: President

               If to Executive, to:




         (ii)  This Agreement shall be binding upon Sterling Software and
               Executive and their respective successors, assigns, heirs and
               personal representatives.

         (iii) The substantive laws of the State of Texas shall govern the
               validity, construction, enforcement and interpretation of the
               provisions of this Agreement.

          (iv) No provision of this Agreement may be modified, waived or
               discharged unless such waiver, modification or discharge is
               agreed to in writing signed by the Executive and Sterling
               Software.  No waiver by either party hereto at any time of any
               breach by the other party hereto or compliance with any condition
               or provision of this Agreement to be performed by such other
               party will be deemed a waiver of similar or dissimilar provisions
               or conditions at the same or at any prior or subsequent time.  No
               agreements or representations, oral or otherwise, expressed or
               implied with respect to the subject matter hereof have been made
               by either party which are not set forth expressly in this
               Agreement.  References to Sections are to references to Sections
               of this Agreement.

                                      -4-
<PAGE>
 
     10.  Termination of Prior Agreements.  The [title of agreement] between
          -------------------------------                                   
          Executive and Sterling Software, dated _______________, as amended to
          the date hereof (the "Prior Agreement"), shall terminate automatically
          and shall thereafter be of no further force or effect; provided,
          however, that if this Agreement is held wholly invalid, unenforceable
          or otherwise illegal, the preceding clause shall have no effect and
          the Prior Agreement shall be deemed to have continued at all times in
          force and effect.  Subject to the foregoing proviso, this Agreement
          supersedes all prior agreements, arrangements and understandings with
          respect to the subject matter hereof.

     Executed by the parties hereto as of the date first set forth above.


                                    EXECUTIVE



                                    ---------------------------------
                                    Name:
                                         ----------------------------

                                    STERLING SOFTWARE, INC.



                                    By:
                                       ------------------------------
                                       Sterling L. Williams
                                       President and
                                       Chief Executive Officer


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