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From: overmyer@gmuvax.gmu.edu
Newsgroups: comp.specification,comp.software-eng
Subject: Re: Complexity in making changes to requirements.
Message-ID: <1991May30.205504.51382@gmuvax.gmu.edu>
Date: 31 May 91 01:55:04 GMT
References: <1991May30.133505@axion.bt.co.uk> <1991May30.171315.4195@netcom.COM>
Organization: George Mason University, Fairfax, VA.
Lines: 40

In article <1991May30.171315.4195@netcom.COM>, jls@netcom.COM (Jim Showalter) writes:
>>What are the factors contribute to the complexity in making 
>>changes to the requirements specification?
> 
> There are a number of factors (I discussed requirements complexity
> in a recent post to this group, so please see that for details),
> but I think by far the most significant factor is the degree to
> which the requirements specify IMPLEMENTATION decisions as opposed
> to just the requirements.
> 
Consider also a specification quality attribute I call maintainability.  This
attribute refers to the maintainability of the specification itself.  There are
a variety of factors which have an impact on the maintainability of a particular
spec including:

modifiability
traceability
annotation
organization
understandability
cross referencing
electronic storage scheme

Definitions for these quality factors can be found in IEEE/ANSI Standard
830-1984 and other related documents.  A possible metric of maintainability
would be the traditional concept of MTTR or better still, MTTC (mean-time-to-
change).  In addition, one might be able to apply the SE concepts of coupling
and cohesion in some sense between specification statements or sections and
derive some interesting metrics.

I hope this is useful.

***********************************************************************
Scott P. Overmyer
Center of Excellence in C3I
Information Systems and Systems Engineering
George Mason University                      Phone: 703.764.6523
Fairfax, Virginia 22030-4444 USA             Fax:   703.764.6526
email: overmyer@gmuvax2.gmu.edu
***********************************************************************