Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sdd.hp.com!usc!hacgate!ashtate!alanw
From: alanw@ashtate (Alan Weiss)
Newsgroups: comp.software-eng
Subject: Re: Software Cost Estimation
Message-ID: <1990Dec12.215401.27859@ashtate>
Date: 12 Dec 90 21:54:01 GMT
References: <5676@taylord>
Organization: Ashton-Tate, Inc., Torrance, CA
Lines: 88

In article <5676@taylord> taylord@Software.Mitel.COM (Don Taylor) writes:
>What is the current thinking on software cost estimation models?
>
>A few years ago Barry Boehm's COCOMO models seemed to be the definitive
>work of the day, and I was wondering where things had gone in this arena
>since then.  I have a few questions:
>
>Is COCOMO still used?  

COCOMO, REVEC, etc are still used in more traditional development
environments by Development/QA/Project Managers who want to verify
their instincts :-)

>Are there software packages available that implement the COCOMO models?

SLIM (Software Life Cycle Management), by Quantitative Software Management, Inc.
In 1987, when my version (2.0) was released the were located at:

	QSM
	1057 Waverley Way
	McLean, VA  22101
	(703) 790-0055

I make no claims that this address nor phone number is still valid.
In my experience, SLIM's estimation skills varied widely with the
nature of the project (system, applications, enabling) and YOUR
estimation skills.  It fell out of favor at one firm I worked at,
but this was probably due more to the force-fed nature of the
tool adaptation process.

>One of the problems that I have with COCOMO and other LOC-based models
>is that it is based upon a program parameter (lines of code) that is not
>known until the latter phases of a project.  Is there a useful cost
>estimation model around that is based upon an early phase deliverable,
>say the requirements specification, that has been shown to work for a
>significant number of projects?

I would STRONGLY suggest you look into Function Point Analysis.
When tied into your already previously done :-)  Quality Function
Deployment Analysis (House of Quality), F(x) Point Analysis is MUCH
more predictive, IMHO.  The problem is two-fold in adaptation:

	1.  It is a LOT of up-front work, and requires very
	    detailed Functional and Design specifications.
	2.  Political:  it requires a LOT of up-front work :-)
	    In short, you must have management and staff buy-in
	    that this is worthwhile.  The Urge to Code always
	    comes ....

>COCOMO assumes that a waterfall model of sw. development is used.
>Although this is still widely used for large projects, it is falling
>out of fashion.  Are there any cost estimation models available for the
>newer development models, eg. spiral development, rapid prototyping?  

Its a funny thing about the ol' Waterfall Model:  like Mark Twain,
rumors of its demise are greatly exaggerated.  There is a HUGE gulf
between what the researchers (such as Dr. Barry Boehm, for whom
I have the greatest respect) are doing and what the worker-bees
are doing.  When there IS a process model, it is almost invariably
some "tailored"/bastardized version of the Waterfall.

When there ISN'T a development methodology/process model, its
called "rapid prototyping."  :-(

The exception is clearly Object Oriented Systems.  OOPS is a
different beast, for which I am just now exploring.  DOES ANYONE
HAVE EXPERIENCE IN AN OOPS ENVIRONMENT?

>Thank you in advance,
>
>Don Taylor (613)-592-2122 x 3007	 mitel!taylord@uunet.uu.net
>Mitel Corp.				 ...!uunet!mitel!taylord    
>350 Legget Drive, Kanata		
>Ontario, Canada, K2K 1X3		
>

Hope I've helped.  My profession is Software Quality Assurance
and System Test, as well as Project Management.  I have the scars
and burn marks to prove it!


.__________________________________________________________.
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