2nd !~rge, wf!w-;are engineering h;ls cc:nccrned ilseif with r&li+ wrli slructured prohlcms. fmusing on the dcls~led dc+n ;rnd coding phssrs of the development cycle. However. ~hetc ia sukstrntial a& today for improved understanding of 1hp.w ph.~ses of ihr dcvciopmenl cycle lhet are Inherently fuzzy or lsckiag in slT3clure. PrLbcmincnt among thcsc fuvp problem CITC~S is lhr dclarmimtlion of il s:islem's inrtial functional requtrsmcnls +md their decomposilion inlo a set of design suhprolslems that u-ill serve ns lhe bitsis for Jc~ailed design. This paper prescnlh ti new mrlhchiuh~g) for aiding P syslem archilect m ntrrying t9n1 lhrw .lclivilics. Some cxpericnce with this rn~~~tawl0lo~y 8s also rcporlrd. h'cru~&.r: Qustcm design. system nrchilcclurc. design melhod-olc9gy. requirements lipcciAcihIi0n, requiremems de composition. !%I k tldf is nn Assislrnl Professor aI the School of Business Administwtion. The University of Western Onr#rio. Formerly he tau ht nl Queen's Ilnivarsity, Kingston an i III lhe Sloan School of Manngelnent, M.I.T. He has also worked us a manngement consultant with Woods. Gordon & Co.. Toronto, and as a re.search engineer cthS$nta;:;d 11 dto. Hc holds 8. SC.. . . . L B.A. dcgrecs from Queen's Univers;ly. and a Ph.D. in lnformstion Syntems from M.I.T. His current research mt$rcsta centrc on monngcmcnt of the informulion systems function. * Author's currcnl .&ircss. Sch~l ol' I?usincss Adminislrallc-n.