EXHIBIT 99.3
 
                  CONSENT OF PERSON ABOUT TO BECOME A DIRECTOR
 
    I, Michael F. Bosworth, hereby consent to the use in the Registration
Statement on Form S-4 of Summit Design, Inc. (the "Company") to which this
consent is filed as an exhibit and the Joint Proxy Statement/Prospectus included
therein, of my name as a person about to become a director of the Company.
 
                                          /s/ Michael F. Bosworth
 
                                          Michael F. Bosworth
 
September 30, 1998