Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!apple!gem.mps.ohio-state.edu!ginosko!uunet!munnari.oz.au!sharam
From: sharam@munnari.oz.au (Sharam Hekmatpour)
Newsgroups: comp.software-eng
Subject: Re: Information Systems is an Engineering Discipline
Message-ID: <2291@munnari.oz.au>
Date: 4 Oct 89 05:52:17 GMT
References: <1142@svx.SV.DG.COM> <34399@regenmeister.uucp> <5296@eos.UUCP> <EJP.89Oct3090900@abvax.icd.ab.com>
Sender: news@cs.mu.oz.au
Reply-To: sharam@munmurra.UUCP (Sharam Hekmatpour)
Distribution: comp.edu
Organization: Comp Sci, University of Melbourne
Lines: 44

In article <EJP.89Oct3090900@abvax.icd.ab.com> ejp@abvax.icd.ab.com (Ed Prochak) writes:
>	The problem has been that we don't build models.
>There has been proposals that we build prototypes instead.
>This may be okay as long as the prototype never leaves the
>development lab. Prototypes have to be treated as throw-aways,
>especially when they work!
>	My personal opinion is that prototypes are not good enough,
>and that models of software systems are possible. What the techniques
>will be, I don't know. I agree that verbal descriptions cannot be good
>enough. Pictures are better (data flow diagrams and the like) but they
>aren't models, they can't be easily tested. There must be something
>we can use. Suggestions? Opinions?

My opinion is that prototypes and models are both good, so long as we
understand their limitations. Any abstraction or simplification -- and
this is exactly what models and prototypes lead to -- involves loss of
information. This is not necessarily bad, but the trick is to decide
WHEN to abstract WHAT and HOW. I strongly belive that no tool or
language can answer these questions. The only reliable source for
answers has been, and still is, EXPERIENCE. 
	In this respect, systems that have been developed for decades
over and over again pose no problem, since there is such a vast body
of knowledge and experience gathered around them. The real problem are
NOVEL systems which, because of the success of this industry, are
growing in number. Because we know little about the application domain
of such systems, and because our experience from other systems does not
usually scale up to such systems, development runs into complications.
	Now, compare this to other engineering disciplines. There, novel
systems are few and far in between, so these difficulties are far less
expressed.
	Hoping to find 'something' that can all of a sudden rescue us
from this maze is like trying to answer unknown questions. Sure, there
are notations, techniques, and ideas that are generally useful, but
there is NO simple, universal solution. I for one think that our
efforts are better spent thinking how we might train "Great Designers"
(see F. Brookes) than to strive for "Great Notations". If only 1 in 10
people in this industry were as good as the best, we would have no
problem to worry about.

+----------------------------------------------+
| Sharam Hekmatpour <sharam@munnari.oz.au>     |
| Computer Science Dept., Melbourne University |
| Parkville, Victoria, Australia 3052          |
+----------------------------------------------+