waterfall (was Re: REPOST: Re: Book "python programming patterns". anybody read this??)
gmcm at hypernet.com
Mon Dec 31 15:40:18 CET 2001
Alex Martelli wrote:
> This is also known as the "waterfall model" of software development.
> It just doesn't work, as many decades of industry experience have amply
The "waterfall" model comes from the days when most development was
mainframe batch systems. It "worked" (to some limited degree) in that
environment because of the following conditions:
- there were only a half-dozen or so basic building blocks in mainframe
batch systems (sort, merge, select, extract...)
- the scope of the projects (successfully managed through "waterfall") was
generally tiny compared to the scope of the system in which they fit
- there were senior people on the project who could balance the "top down"
with some "bottom up", but keep it secret
Violate any one of those (too many technical choices; too big a system; or
people who aren't very familiar with the system's context) and the resultant
system was iteration 1 of an iterative prototype too expensive to complete.
More generally, you could describe a successful "waterfall" project as an
iterative prototype that worked the first time through.
What Peter had right was that *thinking* about the problem is always
necessary, even in an iterative prototype :-).
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