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From: scotth@boulder.Colorado.EDU (Scott Henninger)
Newsgroups: comp.software-eng
Subject: Re: CASE - The Emperor has no clothes on!
Message-ID: <23167@boulder.Colorado.EDU>
Date: 6 Jul 90 16:48:54 GMT
References: <5212@stpstn.UUCP> <1990Jun18.101127.11907@axion.bt.co.uk>
Sender: news@boulder.Colorado.EDU
Reply-To: scotth@boulder.Colorado.EDU (Scott Henninger)
Organization: University of Colorado at Boulder
Lines: 29

In Article 3980 pyoung@axion.bt.co.uk (Pete Young) writes:

> In that sense all materials are well-understood. Properties of new
> materials can easily be calculated and verified by testing. Moreover,
> an engineer is able to rely on the fact that any given piece of
> material will have mechanical properties between certain limits.
> This arises from having a quality control system to produce consistent
> materials. 

This is precisely where the bridge building analogy breaks down.  The
materials used are *physical* entities that obey the *static* laws of
physics.  Software more often than not deals with *conceptual* entities
that evolve and change *dynamically*.  The physical constraints on
software are few and far between, and where they do exist (say in the
form of programming languages), they're subject to change (new
programming languages, new language features).

A more useful analogy is American law.  In this domain the constraints
are conceptual and subject to changes, with few exceptions.  Murder will
always be illegal, but each case is different and must be scrutinized
carefully to determine how the situation should be handled.

After 200 years of practice, we still have not been able to engineer a
perfect (or close approximation thereof) legal system.  The question is
whether we can expect better for software "engineering"?


-- Scott
   scotth@boulder.colorado.edu