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                                 SUMMIT DESIGN, INC.
                                 EMPLOYMENT AGREEMENT


EMPLOYEE:           C. ALBERT KOOB
EFFECTIVE DATE:     February 14, 1999

This Agreement is entered into as of the above date by and between SUMMIT 
DESIGN, INC., a Delaware corporation ("Summit"), and the above-named employee 
("Koob").

1.   EMPLOYMENT AND DUTIES.  SUMMIT hereby employs Koob to serve and perform 
in the role of Vice President of Finance and Chief Financial Officer; 
provided that, if SUMMIT shall hire a new Vice President of Finance and/or 
Chief Financial Officer prior to the expiration of this Agreement, SUMMIT 
shall employ Koob as a Vice President who shall assist the new Vice President 
of Finance and/or Chief Financial Officer.  Koob agrees to perform the duties 
of these positions to the best of his ability and to devote full time and 
attention to the transaction of SUMMIT's business.

2.   TERM AND TERMINATION.

     (a)  This Agreement shall expire on July 31, 1999.  Koob hereby agrees 
that if he is still an employee of Summit on such date, he will resign his 
employment with Summit.  Both parties acknowledge that the employment created 
herein is Employment-at-Will and may be terminated at any time with or 
without cause under the terms stated herein.

     (b)  In the event that Koob notifies Summit of termination of his 
employment with Summit for any reason other than specified in Section 2(d), 
this Agreement shall terminate as of the date of such notification.  
Termination under this Section 2(b) is "Resignation".  Notwithstanding the 
foregoing, the July 31, 1999 resignation required by Section 2(a) shall not 
constitute a "Resignation" for purposes of this Agreement.

     (c)  In the event that Summit notifies Koob of termination of his 
employment by Summit because Koob willfully abandoned the duties of his 
position or engaged in any criminal practice which the Chief Executive 
Officer and Board of Directors reasonably determines is detrimental or 
harmful to the good name, goodwill, or reputation of Summit, or which does or 
could adversely effect the interests of Summit, then this Agreement shall 
terminate as of the date of such notification; provided, however, that the 
Chief Executive Officer or the Board of Directors shall notify Koob upon the 
commencement of any investigation by either of them into any of Koob's acts 
which may be determined to be a criminal practice.  Termination under this 
Section 2(c) is "Cause".

     (d)  In the event that Koob notifies Summit of his resignation as an
employee of Summit because Summit has required (in writing) Koob to perform
without Koob's consent (in writing) solely in any role other than Vice President
of Finance and Chief Financial Officer, or, 

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in the event that Summit has hired another person in the position of Vice 
President of Finance and/or Chief Financial Officer, in any role other than a 
Vice President who shall assist the new Vice President of Finance and/or 
Chief Financial Officer, then this Agreement shall terminate as of the date 
of such notification.  Termination under this Section 2(d) is "Construction".

     (e) In the event that Summit notifies Koob of termination of his 
employment by Summit for any reason other than specified in Section 2(c) 
and/or 2(d), this Agreement shall terminate as of the date of such 
notification. Termination under this Section 2(e) is "Convenience".

     (f)  Notwithstanding the above, termination of this Agreement shall not 
release Koob from any obligations under Sections 4, 5, 6, and 7 hereof.

3.   COMPENSATION AND BENEFITS.  In consideration of the services to be 
performed by Koob, Summit agrees to pay Koob the compensation and extend to 
Koob the benefits consisting of the following:

     (a)  Annual Base Salary of $160,000, paid twice monthly.

     (b)  Koob shall be provided the right to participate in the health, 
dental, and life insurance programs provided for the senior level executives 
of Summit.

     (c)  Koob shall earn up to two (2) weeks of Paid Time Off during the 
term of this Agreement.  This Paid Time Off shall be available for use as 
earned according to the standard policy of Summit.

     (d)  An allowance for car expenses of $750.00 per month.

     (e)  In the event that (i) this Agreement is terminated for Construction 
as defined in Section 2(d) or Convenience as defined in Section 2(e), or (ii) 
Koob remains employed by Summit pursuant to this Agreement until he resigns 
on July 31, 1999 as provided in Section 2(a), then Summit shall pay Koob 
$13,333.33 per month plus all benefits set forth in Sections 3(b) and 3(d).  
This payment shall continue monthly, with the last payment being made for the 
month ended July 31, 2000; provided, however, that as a condition precedent 
to Koob receiving such payment, Koob must execute the Settlement Agreement in 
the form attached hereto as ANNEX A and the seven (7) day revocation period 
referenced in Section 7 thereof shall have expired; and provided further, 
that if Koob accepts full-time employment from another party, payment of the 
benefit set forth in Section 3(d) shall cease immediately.
     
4.   CONFIDENTIALITY.  Koob acknowledges that certain customer lists, design
work, and related information, equipment, computer software, and other
proprietary products and information, whether of a technical or non-technical
nature, including but not limited to schematics, drawings, models, photographs,
sketches, blueprints, printouts, and program listings of Summit, 

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collectively referred to as "Technology", were and will be designated and 
developed by Summit at great expense and over lengthy periods of time, are 
secret and confidential, are unique and constitute the exclusive property and 
trade secrets of Summit, and any use or disclosure of such Technology, except 
in accordance with and under the provisions of this or any other written 
agreements between the parties, would be wrongful and would cause irreparable 
injury to Summit.  Koob hereby agrees that he will not, at any time, without 
the express written consent of Summit, publish, disclose, or divulge to any 
person, firm, or corporation any of the Technology, nor will Koob use, 
directly or indirectly, for Koob's own benefit or the benefit of any other 
person, firm, or corporation, any of the Technology, except in accordance 
with this Agreement or other written agreements between the parties.

5.   INVENTIONS., All original written material including programs, charts, 
schematics, drawings, tables, tapes, listings, and technical documentation 
which are prepared partially or solely by Koob in connection with employment 
by Summit shall belong exclusively to Summit.

6.   RETURN OF DOCUMENTS.  Koob acknowledges that all originals and copies of 
records, reports, documents, lists, plans, drawings, memoranda, notes, and 
other documentation related to the business of Summit or containing any 
confidential information of Summit shall be the sole and exclusive property 
of Summit, and shall be returned to Summit upon the termination of employment 
for any reason whatsoever or upon the written request of Summit.

7.   COMPLIANCE.  Koob agrees to comply with all of Summit's written 
employment policies, guidelines, and procedures as contained in an employment 
manual, including revisions and additions thereto.

8.   INJUNCTION.  In addition to all other legal rights and remedies, Summit 
shall be entitled to obtain from any court of competent jurisdiction 
preliminary and permanent injunctive relief of any actual or threatened 
violation of any term hereof without requirement of bond, as well as an 
equitable accounting of all profits or benefits arising out of such violation.

9.   WAIVER.  The waiver of either party of a breach of any provision of this 
Agreement shall not operate or be construed as a waiver of any subsequent 
breach thereof.

10.  DISPUTES.  The legal relations of the parties hereunder, and all other 
matters hereunder, shall be governed by the laws of the State of Oregon. 
Unresolved disputes shall be resolved in a court of competent jurisdiction in 
Washington County, Oregon, and all parties hereto consent to the jurisdiction 
of such court.

11.  ENTIRE AGREEMENT.  This Agreement and Annex A hereto set forth the 
entire agreement between the parties hereto, and fully supersedes any and all 
prior agreements or understandings, written or oral, between the parties 
hereto pertaining to the subject matter hereof, including without limitation 
that certain Employment Agreement dated as of October 21, 1995 by and 

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between SUMMIT and Koob.  No modification of amendment hereof is effective 
unless in writing and signed by both parties.

     IN WITNESS WHEREOF, the parties have executed this Agreement as of the 
date first herein above written.

"EMPLOYER":                        SUMMIT DESIGN, INC.:
                                   A Delaware Corporation


                                   By: /s/ Larry J. Gerhard
                                       -------------------------------
                                 Name:    Larry J. Gerhard
                                 Title:   Chief Executive Officer, Summit



"EMPLOYEE":                            /s/ C. Albert Koob
                                       -------------------------------
                                       C. Albert Koob


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