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From: eberard@bse.com (Edward V. Berard)
Newsgroups: comp.object
Subject: Re: OOA vs OOD (was: Booch GOOD - Coad/Yourdon BAD)
Summary: functional decomposition and object-oriented don't mix
Message-ID: <0B010001.imp7d9@bse.com>
Date: 9 Nov 90 12:29:13 GMT
Reply-To: eberard@bse.com
Organization: Berard Software Engineering, Inc.
Lines: 29
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In article <1289@fang.dsto.oz>, dch@aeg.dsto.oz.au (Dave Hanslip) writes:

> I recall a statement I saw on the net some months back that large system
> design should proceed sequentially through steps of SA/SD and OOD. In my
> experience, with a laand very complex system, if one commences with OOD, one is
> overwhelmed by complexity. Cencing with SA/SD allows smaller less complex
> subsystems to be identified to which OOD (a la CRC cards) can then be applied.
> SA/SD (or functional decomposition if you like) is then again applied within
> classes to member functions. 

Functional decomposition approaches localize information around functions,
whereas object-oriented approaches localize information around objects. Using
a functional decomposition approach first breaks apart high level objects
and scatters information on these objects into different functional components.

It is far better to use an object-oriented decomposition technique to partition
your system into manageable pieces to which you can then apply other
object-oriented techniques.

				-- Ed


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Edward V. Berard                                | Phone: (301) 353-9652
Berard Software Engineering, Inc.               | FAX:   (301) 353-9272
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