Path: utzoo!attcan!uunet!samsung!sol.ctr.columbia.edu!src.honeywell.com!skyler.mavd.honeywell.com!djbailey
From: djbailey@skyler.mavd.honeywell.com
Newsgroups: comp.software-eng
Subject: Re: Reusability considered harmful??(!!)
Message-ID: <1991Feb27.103306.3@skyler.mavd.honeywell.com>
Date: 27 Feb 91 16:33:05 GMT
References: <88744@tut.cis.ohio-state.edu> <88431@tut.cis.ohio-state.edu>  <34523@athertn.Atherton.COM>
Lines: 29

In article <34523@athertn.Atherton.COM>, mcgregor@hemlock.Atherton.COM (Scott McGregor) writes:
> I am afraid I am belaboring this point, but it is an important one. 
> In the end, business decisions can only be effectively grounded on
> how the people who implement them actually act, and not merely how they
> OUGHT to act. Humans are wonderous and yet imperfect creatures.  Theories

When I first thought about the sine routine example I described, I came
to two conclusions. The first conclusion, which has been adequately 
defended by others, is that reusable components have to be tested in 
the context of the new application. There's no other way to be sure 
you've picked the right component.

My second conclusion is that specifying or describing reusable 
components is much harder than it seems. We can't reasonably expect 
the component designer to know every possible application for the 
component.

Every time one considers reusing a component, there is a make/buy 
decision.  When the effort required to make the decision is close to 
the effort to make the component, reuse will not happen. This puts 
some very practical limits on how detailed your specification can be.

I don't know if delivering source code is necessary but it is 
necessary to describe the algorithms and processing in detail. It 
would also be very useful to provide a test suite to help the user 
evaluate the software. The test suite would help the user determine if 
some additional special tests are needed.

-- Don J. Bailey