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                                                                    EXHIBIT 10.4


                     AMENDED & RESTATED EMPLOYMENT AGREEMENT

This Amended and Restated Agreement dated as of the 1st day of January, 1999
amends and restates an EMPLOYMENT AGREEMENT (the "Original Employment
Agreement") made as of the 1st day of November, 1997, among JAMES A. PERAKIS of
Wilton, Connecticut, (the "Employee") and Hyperion Software Operations Inc., a
Delaware corporation with offices in Stamford, Connecticut (the "Corporation")
and Hyperion Software Corporation, a Delaware corporation (as amended and
restated, the "Amended Agreement").

         WHEREAS, Hyperion Solutions Corporation, a Delaware corporation,
(hereinafter referred to as "Parent") has become the beneficial owner of all the
issued and outstanding shares of Hyperion Software Corporation ("HSC");

         WHEREAS, the Corporation, HSC and Parent desire to amend and restate
the terms and conditions of the employment of the Employee effective January 1,
1999, and the Employee desires that the terms and conditions of his employment
with the Corporation be amended and restated effective January 1, 1999, on the
terms and conditions hereinafter set forth.

         NOW THEREFORE, in consideration of the mutual covenants and promises of
the parties hereto, the Corporation, HSC, Parent and Employee agree as follows:

         1. Employment: Effective January 1, 1999, the Employee shall serve as a
Senior Advisor to the President of the Corporation, performing such executive
functions appropriate to that position as determined by the Corporation on the
terms and conditions hereinafter stated.

         2. Term of Employment: Subject to Section 6 below, the term of this
Amended Agreement and the Employee's employment by the Corporation pursuant
hereto shall begin as of January 1, 1999 and shall continue in full force and
effect through September 30, 1999. 
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Notwithstanding the above, however, from and after September 30, 1999, except in
the event this Amended Agreement is terminated for cause pursuant to Section
6(c), the Employee, his spouse and each of his children (in each case until such
child reaches age twenty-one (21)) shall be entitled to receive the fringe
benefits described in Section 4(b) hereof or, at the discretion of the
Corporation, a similar alternative, continuing until the Employee reaches, or in
the event of the Employee's prior death, until the Employee otherwise would have
reached, the age of sixty-five (65).

         3. Compensation:

                  (a) The Corporation shall pay the Employee a base salary
("Base Salary") during the term of his employment hereunder equal to $145,000
per annum, payable at the rate of six thousand, forty one dollars and
sixty-seven cents ($6,041.67) on the 15th and last day of each month. This Base
Salary may be increased in an amount to be determined by the Board of Directors
in its sole discretion, but may not be decreased from its then current level.

                  (b) As additional compensation, the Corporation, in the sole
discretion of the Board of Directors, shall pay to Employee an annual
performance bonus based upon objectives proposed by the President and approved
by the Board of Directors. The Employee's annual performance bonus for the term
hereof shall be targeted at fifty (50%) percent of the Employee's Base Salary
for such nine month period provided that the Corporation achieves all of the
goals relating to his annual performance bonus.

         4. Fringe Benefits: During the term of this Amended Agreement and the
Employee's employment by the Corporation pursuant hereto:

                  (a) The Corporation shall provide the Employee with either all
benefits 

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provided to its senior executives generally or to its employees generally, on
the same terms and conditions as applicable thereto, whichever is more favorable
to the Employee.

                  (b) The Corporation shall provide the Employee with basic
major medical and dental insurance for the Employee, his spouse and his children
(in each case until such child reaches the age of twenty-one (21)) which will be
at least equivalent to the Corporation's current medical and dental insurance
plans and in no event be less favorable than the more favorable of either the
medical and dental insurance, respectively, provided to the Corporation's senior
executives generally or its employees generally.

                  (c) The Employee is authorized to incur on behalf of the
Corporation reasonable expenses in connection with the business of the
Corporation. The Corporation will reimburse the Employee for all reasonable
expenses incurred in connection with the business of the Corporation upon the
presentation by the Employee, from time to time, of an itemized account of such
expenditures, which itemized account shall be in conformity with Section 274(d)
of the Internal Revenue Code of 1986, as amended. The Corporation hereby
authorizes the Employee to fly business or first class on any business flights
of over two hours and agrees to reimburse the Employee therefor.

                  (d) The Corporation shall provide the Employee with a term
insurance policy on the life of the Employee in the amount of four (4) times the
Employee's current Base Salary. The Employee will be the owner of said policy
and select the beneficiary thereof and the owner shall have the right to
transfer or change the ownership and/or beneficiary designation. Upon
termination of this Amended Agreement and/or termination of coverage, the then
owner shall have the option to assume the benefits (where such assumption is
permitted under the terms of the relevant policy and/or plan) and obligations
under such policy upon termination of this 

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Amended Agreement and/or termination of coverage and thereafter the Corporation
shall not be required to make premium payments.

                  (e) The Corporation shall provide the Employee with a monthly
automobile allowance equal to $1,000.

                  (f) The Corporation shall continue to maintain its sponsorship
of the Employee's current disability insurance coverage.

                  (g) The Corporation shall provide Employee with and/or
reimburse Employee for his reasonable costs incurred in obtaining, technical
services and equipment and administrative services for an office at the
Employee's home. Employee shall be entitled to use the services of his present
administrative assistant provided at the Corporation's offices for so long as
practicable.

         5. Duties and Extent of Services: Throughout the term of the Employee's
employment under this Amended Agreement, the Employee shall assume the position
of Senior Advisor to the President of the Corporation. The Corporation shall not
change the Employee's duties or title without the Employee's consent. The
Corporation recognizes and acknowledges that this is a part-time position and
that the Employee shall be required to devote no more than an average of ten
(10) business days per month to the affairs of the Corporation. Reflecting the
part-time nature of his employment hereunder, during the term of this Amended
Agreement, Employee may, subject to the terms of the covenant not to compete in
Section 8 hereof, be engaged in or concerned with other employment or
self-employment duties or pursuits, without the prior written consent of the
Corporation. Nothing herein nor in Section 8 hereof, shall prohibit Employee
from serving on the board of directors of a corporation, which at some time in
future competes with the Corporation or the Parent, provided that such
corporation, did not, at the time 


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Employee joined that corporation's board of directors, compete with the Company
or the Parent or, to the best knowledge of Employee after due inquiry, intend to
compete with the Company or the Parent in the future.

         6. Termination: This Amended Agreement and the Employee's employment
hereunder shall terminate (i) on September 30, 1999, or if first, (ii) upon the
occurrence of any of the following events, and upon any such termination the
Employee will have no right to severance pay or salary, bonus or benefit
continuation except as expressly provided in this Amended Agreement:

                  (a)      The Employee's death.

                  (b) The termination of the Employee's employment hereunder by
the Corporation, at its option, to be exercised by written notice from the
Corporation to the Employee after the Employee's incapacity or inability to
further perform his services as contemplated herein for a period of six (6)
consecutive months due to the fact that his physical or mental health shall have
become impaired so as to make it impossible or impractical for him to perform
the duties and responsibilities contemplated for him hereunder as evidenced by
the written medical report of a doctor reasonably acceptable to the Corporation
and the Employee.

                  (c) The termination for cause (as hereinafter defined) of the
Employee's employment hereunder by Corporation, at its option, to be exercised
by written notice from Corporation to the Employee.

                  (d) At any time without cause and without notice. If the
Corporation terminates this Amended Agreement and the Employee's employment
without notice and without cause pursuant to this Section 6(d) for a reason not
specified in subparagraphs (a), (b), (c), and/or (f) of this Section 6, then:
(i) the Corporation shall provide to the Employee as severance pay, a 


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total amount equal to (A) his Base Salary, payable in twelve (12) consecutive
monthly installments (without interest) beginning one (1) month after such
termination, plus (B) the fringe benefits described in Section 4(b) hereof, or
at the discretion of the Corporation, a similar alternative, commencing on the
effective date of the Employee's termination by the Corporation pursuant to this
Section 6(d) and continuing until the Employee reaches the age of sixty-five
(65) or, should he have died earlier, until the Employee otherwise would have
reached the age of sixty-five (65); and (ii) the option to purchase 150,000
shares of common stock, $.01 par value, of HSC granted to Employee under the
option agreement dated September 19, 1996 between Employee and HSC (the "Option
Agreement"), as converted into an option to purchase 142,500 shares of common
stock, $.001 par value, of Parent pursuant to the merger effected under the
Agreement and Plan of Merger dated May 25, 1998 among Arbor Software
Corporation, HSC and HSC Merger Corp. (the "Option"), shall become fully vested
and exercisable in its entirety.

                  (e) For purposes of paragraph 6(c) the term "cause" shall
include only the following: 

                      (i) Employee's failure or refusal (even after notice of
termination is given by either party pursuant to this Amended Agreement) to
perform the services specified herein, or to carry out any reasonable and lawful
directions of the Board of Directors of the Corporation with respect to the
services to be rendered hereunder or the manner of rendering such services other
than by reason of his disability as described in Section 6(b) hereof; provided,
however, that (A) such failure or refusal is material, and (B) Employee is given
reasonable notice and explanation of each refusal or failure, and reasonable
opportunity to cure such refusal or failure, and no cure has been effected
within a reasonable time after notice;

                      (ii) Conviction of a felony which can reasonably be 
expected to have a 



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material adverse impact on the Corporation's business or reputation;

                      (iii) Fraud or embezzlement involving the assets of the
Corporation, its customers, suppliers or affiliates; or

                      (iv) Violation of the provisions of Sections 7, 8,
and/or 9 of this Amended Agreement by the Employee.

                  (f) (i) If there is a Change in Control of the Corporation (as
hereinafter defined) that occurs during the term of employment described in this
Amended Agreement but prior to the expiration or termination of this Amended
Agreement and, within twelve (12) months after the Change in Control, Employee
terminates his employment for Good Reason (as hereinafter defined), then the
Corporation shall provide to the Employee: (A) as severance pay a total amount
equal to twice the Employee's annual Base Salary at the time of the Change in
Control payable in twenty-four (24) equal consecutive installments in accordance
with the Corporation's normal payroll practices (without interest) beginning on
the first regularly scheduled payday after such termination (the period during
which employee receives severance pay hereinafter referred to as the "Severance
Period"), plus (B) the fringe benefits described in Section 4(b) hereof and
continuing until the Employee reaches the age of sixty-five (65) or, should he
have died earlier, until the Employee otherwise would have reached the age of
sixty-five (65). It is expressly understood that nothing in the foregoing will
prevent either party from taking such legal action as may be necessary to
enforce the terms of this Amended Agreement.

                       (ii) As used in this Amended Agreement, the following 
terms have the meanings set below:

                                    (A) "Affiliate" of a person means any person
                  directly or indirectly controlling, controlled by or under
                  common control with the first 


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<PAGE>   8
person.

                                    (B) "Associate" has the meaning ascribed
                  thereto in Rule 12b-2 under the Exchange Act (as defined
                  below) as in effect on the date hereof.

                                    (C)  "Change in Control" means the 
                  occurrence of any of the following events:

                                             (I) Merger, Consolidation, Etc. The
                  Corporation or Parent is merged or consolidated or reorganized
                  into or with another corporation or other legal person, and as
                  a result of such merger, consolidation or reorganization less
                  than a majority of the combined voting power of the
                  then-outstanding securities of such surviving, resulting or
                  reorganized corporation or person immediately after such
                  transaction is held in the aggregate by the holders of the
                  then-outstanding securities entitled to vote generally in the
                  election of directors of the Corporation or Parent ("Voting
                  Stock"), as the case may be, immediately prior to such
                  transaction;

                                             (II) Sale of Assets. The
                  Corporation or Parent sells or otherwise transfers all or
                  substantially all of its assets to any other corporation or
                  other legal person, and as a result of such sale or transfer
                  less than a majority of the combined voting power of the
                  then-outstanding securities of such corporation or person
                  immediately after such sale or transfer is held in the
                  aggregate by the holders of Voting Stock of the Corporation or
                  Parent immediately prior to such sale or transfer;

                                             (III) Change in Beneficial
                  Ownership. There is a report filed on Schedule 13D or Schedule
                  14D-1 (or any successor schedule, form or



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<PAGE>   9
                  report), each as promulgated pursuant to the Exchange Act (as
                  hereinafter defined), disclosing that any "person" (as such
                  term is used in Section 13(d)(3) or Section 14(d)(2) of the
                  Exchange Act) has become the "beneficial owner" (as such term
                  is used in Rule 13 d-3 under the Exchange Act) of securities
                  representing more than 50% of the Voting Stock of the Parent;

                                             (IV) Filing of Certain Reports of
                  Change of Control. The Parent files a report or proxy
                  statement with the Securities and Exchange Commission pursuant
                  to the Exchange Act disclosing in response to Form 8-K or
                  Schedule 14A (or any successor schedule, form or report or
                  item therein) that a change in control of the Parent has
                  occurred; or

                                             (V) Change in Board Composition. If
                  during any period of two consecutive years, individuals who at
                  the beginning of any such period constitute the Board cease
                  for any reason to constitute at least a majority thereof,
                  unless the election, or the nomination for election by the
                  Parent's stockholders, of each director of the Parent first
                  elected during such period was approved by a vote of at least
                  a majority of the directors then still in office who were
                  directors of the Parent at the beginning of any such period;
                  provided, however, that a "Change in Control" shall not be
                  deemed to have occurred for purposes of this Amended Agreement
                  solely because (i) the Corporation or Parent, (ii) an entity
                  in which the Corporation or Parent directly or indirectly
                  beneficially owns 50% or more of the voting securities, or
                  (iii) any Corporation or Parent-sponsored employee stock
                  ownership plan or any other employee benefit plan of the
                  Corporation or Parent, either files or becomes obligated to
                  file a report or a proxy statement under or in



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                  response to Schedule 13D, Schedule 14D-1, Form 8-K or Schedule
                  14A (or any successor schedule, form or report) under the
                  Exchange Act, disclosing beneficial ownership by it of shares
                  of Voting Stock or because the Corporation or Parent reports
                  that a change in control of the Corporation or Parent has
                  occurred by reason of such beneficial ownership.

                                    (D) "Exchange Act" means the Securities
                  Exchange Act of 1934, as amended from time to time.

                                    (E) "Good Reason" means that, following a
                  Change in Control and without Employee's written consent:

                                             (I) there has been a significant
                  diminution in the nature or scope of Employee's authority,
                  duties or responsibilities in effect immediately prior to the
                  Change in Control; or

                                             (II) there has been a reduction in
                  Employee's annual Base Salary in effect immediately prior to
                  the Change in Control or an adverse change in Employee's total
                  compensation such that Employee's compensation and benefits in
                  the aggregate are 25% below his aggregate compensation and
                  benefits in effect immediately prior to the Change in Control;
                  or

                                             (III) the principal place of
                  Employee's employment is relocated to a place that is more
                  than 25 miles from the principal place of Employee's
                  employment immediately prior to the Change in Control or
                  Employee is required to be away from his office in the course
                  of discharging his duties and responsibilities 25% more than
                  was required prior to the Change in



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<PAGE>   11
         Control.

                  (g) In the event of any termination pursuant to this Section
         6, the Corporation shall pay to the Employee such portion of his Base
         Salary as has been earned by the Employee as of the date such
         termination becomes effective, a pro rata portion of any bonus due
         Employee through the date of his termination (unless Employee is
         terminated for cause pursuant to Section 6(c) hereof in which case no
         bonus shall be paid or payable) and payment for any accrued unused
         vacation time, all less (i) all applicable taxes, (ii) any other
         required withholdings, and (iii) any other amounts the Employee may owe
         to the Corporation, and thereafter the Employee shall have no claim for
         any further compensation from the Corporation (including its parents,
         subsidiaries, division, affiliates, successors and assigns) except as
         otherwise expressly provided for herein. The Employee's receipt of such
         amounts and/or any severance payments provided for by this Amended
         Agreement, will constitute a full accord and satisfaction (and in the
         case of severance pay and Option acceleration, liquidated damages) in
         full and final settlement of any and all amounts owed by the
         Corporation (including its subsidiaries, parents, divisions,
         affiliates, successors and assigns) to the Employee under this Amended
         Agreement or under the Original Employment Agreement , under any
         severance plan, practice or policy or otherwise.

                  (h) The Employee hereby waives and releases any rights or
         claims he may have or have had under Section 7(f) or 7(h) of the
         Original Employment Agreement.

                  (i) In the event that the Employee's employment with the
         Corporation terminates pursuant to any term of this Amended Agreement,
         then the Employee agrees to resign from all officers and directorships
         he may then hold with the Corporation and/or Parent (other than
         membership of the board of directors of Parent) immediately upon the
         Corporation's request

         7. Restrictions On Employee: During the period commencing on the date
hereof and 



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<PAGE>   12
ending two (2) years after the termination of the Employee's employment with the
Corporation for any reason, the Employee shall not (a) directly or indirectly
induce or attempt to induce any of the employees of the Corporation (including
its subsidiaries, parents, divisions, affiliates, successors and assigns) to
leave the employ of the Corporation (including its subsidiaries, parents,
divisions, affiliates, successors and assigns), or (b) hire, or assist any other
entity or person in the recruitment or hiring of, any employees of the
Corporation (including its subsidiaries, parents, divisions, affiliates,
successors and assigns). Following the termination of the Employee's employment
with the Corporation for any reason, the Employee also shall not make any
defamatory, slanderous and/or libelous statements whatsoever concerning the
Corporation or its affiliated companies and/or their businesses, operations,
technologies, products, services, marketing strategies, pricing policies,
management, affairs, financial condition, directors, shareholders, officers,
employees and/or agents.

         8. Covenant Not to Compete: During the period commencing on the date
hereof, and ending two (2) years after the termination of the Employee's
employment for any reason, (a) the Employee shall not, except as a passive
investor in publicly held companies (i.e., owning or holding beneficially or of
record 1% or less of the voting shares of an entity), engage in, or own or
control any interest in, or act as principal, director, officer or employee of,
or consultant to, any firm, corporation, entity or person which is in
competition with the Corporation or its Parent in the states/locations listed in
Rider A, attached hereto; and (b) the Employee shall not, on behalf of any firm,
corporation, entity or person which is in competition with the Corporation
and/or the Parent, solicit or do business with any customer of the Corporation
(including its subsidiaries, parents, divisions, affiliates, successors and
assigns) or any potential customer of the Corporation (including its
subsidiaries, parents, divisions, affiliates, successors and assigns). 



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<PAGE>   13
If the covenants set forth in this Section 8 are determined by a court of
competent jurisdiction to be overbroad in duration or geographic scope, then the
provisions will not be invalidated or rendered unenforceable but rather will be
deemed enforceable to the maximum extent permitted by law.

         9. Proprietary Information:

                  (a) For purposes of this Amended Agreement, "proprietary
information" shall mean any information relating to the business of the
Corporation (including its parents, subsidiaries, affiliates, successors and
assigns) or any entity in which the Corporation (including its parents,
subsidiaries, affiliates, successors and assigns) has a controlling interest
that has not previously been publicly released by duly authorized
representatives of the Corporation and shall include (but shall not be limited
to) confidential information encompassed in all proposals, marketing and sales
plans, financial information, costs, pricing information, computer programs
(including without limitation source code, object code, algorithms and models),
customer information, customer lists, and all methods, concepts, know-how or
ideas in or reasonably related to the business of the Corporation (including its
parents, subsidiaries, affiliates, successors and assigns) or any entity in
which the Corporation (including its parents, subsidiaries, affiliates,
successors and assigns) has a controlling interest. The Employee agrees to
regard and preserve as confidential all proprietary information, whether he has
such information in his memory or in writing or other tangible or intangible
form. The Employee will not, without written authority from the Corporation to
do so, directly or indirectly, use for his benefit or purposes, nor disclose to
others, either during the term of his employment hereunder or thereafter, except
as required by the conditions of his employment hereunder, any proprietary
information. The Employee agrees not to remove from the premises of the
Corporation or any 


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<PAGE>   14
subsidiary or affiliate of the Corporation, except as an employee of the
Corporation in pursuit of the business of the Corporation or any of its
subsidiaries, affiliates or any entity in which the Corporation has a
controlling interest, or except as specifically permitted in writing by the
Corporation, any document or object containing or reflecting any proprietary
information. The Employee recognizes that all such documents and objects,
whether developed by him or by someone else, are the exclusive property of the
Corporation. The restrictions set forth in this Section 9(a) shall not apply to
information which (i) was known to the Employee at the time he was told of it by
the Corporation, (ii) is known to the industry or public generally, (iii) was
subsequently disclosed to the Employee by a third party having the right to do
so, or (iv) is required to be disclosed by law.

                  (b) All proprietary information and all of the Employee's
interest in trade secrets, trademarks, computer programs, customer information,
customer lists, employee lists, products, procedure, copyrights, patents and
developments hereafter to the end of the period of employment hereunder
developed by the Employee as a result of or in connection with, his employment
hereunder, shall belong to the Corporation; and, without further compensation,
but at the Corporation's expense, forthwith upon request of the Corporation,
Employee shall execute any and all such assignments and other documents and take
any and all such assignments and other documents and take any and all other
action as Corporation may reasonably request in order to vest in Corporation all
the Employee's right, title and interest in and to all of the aforesaid items,
free and clear of liens, charges and encumbrances.

                  (c) The Employee expressly agrees that the covenants set forth
in Section 7, 8, and 9 of this Amended Agreement are being given to the
Corporation in connection with the employment of the Employee by the Corporation
and that such covenants are intended to protect 



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<PAGE>   15
the Corporation against competition by the Employee, within the terms stated, to
the fullest extent deemed reasonable and permitted in law and equity. In the
event that the foregoing limitations upon the conduct of the Employee are beyond
those permitted by law, such limitations, both as to time and geographical area,
shall be, and be deemed to be, reduced in scope and effect to the maximum effect
permitted by law.

         10. Injunctive Relief: The Employee acknowledges that the injury to the
Corporation resulting from any violation by him of any of the covenants
contained in Sections 7, 8, and 9 of this Amended Agreement will be of such a
character that it cannot be adequately compensated by money damages, and,
accordingly, the Corporation may, in addition to pursuing its other remedies,
obtain an injunction from any court having jurisdiction of the matter
restraining any such violation; and no bond or other security shall be required
in connection with such injunction.

         11. Representation of Employee: The Employee represents and warrants
that neither the execution and delivery of this Amended Agreement nor the
performance of his duties hereunder violates the provisions of any other
agreement to which he is a party or by which he is bound.

         12. Parties; Non-Assignability by Employee: As used herein, the term
"Corporation" shall mean and include the Corporation and any parent or
subsidiary thereof and any successor thereto unless the context indicates
otherwise. Except as otherwise provided and except with respect to the
Employee's rights with respect to the common stock or options to purchase common
stock owned or to be received by the Employee, this Amended Agreement and all
rights hereunder are personal to the Employee and shall not be assignable by him
and any purported assignment shall be null and void and shall not be binding on
the Corporation. This Amended Agreement shall be assignable and transferable by
the Corporation pursuant to (a) the sale of all 


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<PAGE>   16
or substantially all of the assets of the Corporation or Parent to any related
or unrelated person, (b) the sale of 50% or more of the voting stock of the
Corporation or Parent to any related or unrelated person or entity in a single
transaction or series of related transactions within a six (6) month period, or
(c) a merger or consolidation of the Corporation or Parent with any related or
unrelated person or entity.

         13. Entire Agreement: This Amended Agreement, the Original Employment
Agreement (through the period ending December 31, 1998) and the Option Agreement
(as modified by the Original Employment Agreement) contain the entire agreement
between the parties hereto with respect to the transactions contemplated herein
and supersede all other prior agreements and understandings, oral or written,
between the Employee and the Corporation, the Employee and HSC and/or the
Employee and Parent, and all other previous representations, negotiations,
commitments, and writings with respect thereto.

         14. Indemnification; D&O Coverage:

                  (a) The Corporation agrees that it will not, without the
consent of the Employee, which consent will not be unreasonably withheld,
conditioned or delayed, amend or alter the provisions of its Certificate of
Incorporation relating to indemnification of officers and directors if the
effect of such amendment or alteration would materially reduce the protection
presently provided to the Employee by such provisions.

                  (b) The Corporation agrees that it will continue to maintain
directors and officers liability insurance coverage for the Employee during the
term of this Amended Agreement on terms commensurate with comparable companies
in the software industry, provided such coverage is available at reasonable
rates.

         15. Amendment or Alteration: No amendment or alteration of the terms of
this 



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<PAGE>   17
Amended Agreement shall be valid unless made in writing and signed by all of the
parties hereto.

         16. Choice of Law: This Amended Agreement shall be governed by the laws
of the State of Connecticut without regard to the principles of conflicts of law
thereof.

         17. Notices: Any notices required or permitted to be given under this
Amended Agreement shall be sufficient if in writing, and if sent by registered
mail to the residence of the Employee, or to the principal office of the
Corporation, respectively.

         18. Waiver of Breach: The waiver by any party hereto of a breach of any
provision of this Amended Agreement shall not operate or be construed as a
waiver of any subsequent breach by any of the parties hereto.

         19. Binding Effect: The terms of this Amended Agreement shall be
binding upon and inure to the benefit of the parties hereto and their respective
personal representatives, heirs, administrators, successors, and permitted
assigns.

         20. Severability: In the event that any provision of this Amended
Agreement is held by a court of competent jurisdiction to be illegal or
unenforceable, such provision shall be deleted from this Amended Agreement,
which shall otherwise remain in full force and effect and binding upon the
parties hereto.

         21. Captions: The captions contained herein are for convenience only
and shall not affect the interpretation of this Amended Agreement.

         22. Payment for Exercise of Stock Options: With respect to the
Employee's vested and exercisable option rights to purchase shares of Parent's
common stock, the Corporation will, upon the Employee's request, seek all
approval necessary to permit the option exercise price for 



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<PAGE>   18
such rights (and any applicable withholding tax) to be paid by delivery of
shares of Parent's common stock having an aggregate fair market value equal as
of the date of exercise to such option exercise price (and any applicable
withholding tax), in accordance with the terms of the plan(s) and/or
agreement(s) governing such option rights.



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<PAGE>   19
         IN WITNESS WHEREOF, the parties have executed this Amended Agreement as
of the day and year first above written.

                               EMPLOYEE:

                               /s/ James A. Perakis
                               ------------------------------------
                               James A. Perakis

                               CORPORATION:

                               HYPERION SOFTWARE OPERATIONS INC.

                               By /s/ Stephen V. Imbler
                                  ---------------------------------
                               Stephen V. Imbler
                               Its Senior Vice President & CFO

                               HYPERION SOFTWARE CORPORATION

                               By /s/ Stephen V. Imbler
                                  ---------------------------------
                               Stephen V. Imbler
                               Its Senior Vice President & CFO

                               HYPERION SOLUTIONS CORPORATION

                               By: /s/ Stephen V. Imbler
                                  ---------------------------------
                               Stephen V. Imbler
                               Its Senior Vice President & CFO


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<PAGE>   20
                                     RIDER A

            Alabama                                     Oregon
            Alaska                                      Pennsylvania
            Arizona                                     Rhode Island
            Arkansas                                    South Carolina
            California                                  South Dakota
            Colorado                                    Tennessee
            Connecticut                                 Texas
            Delaware                                    Utah
            Florida                                     Vermont
            Georgia                                     Virginia
            Hawaii                                      Washington
            Idaho                                       West Virginia
            Illinois                                    Wisconsin
            Indiana                                     Wyoming
            Iowa                                        Australia
            Kansas                                      Brazil
            Kentucky                                    Canada
            Louisiana                                   England
            Maine                                       France
            Maryland                                    Germany
            Massachusetts                               Hong Kong
            Michigan                                    Israel
            Minnesota                                   Japan
            Mississippi                                 Mexico
            Missouri                                    Netherlands
            Montana                                     Republic of Ireland
            Nebraska                                    Singapore
            Nevada                                      United Kingdom
            New Hampshire
            New Jersey
            New Mexico
            New York
            North Carolina
            North Dakota
            Ohio
            Oklahoma

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