[comp.software-eng] COCOMO software estimating model

ewa@csdgwy.csd.unsw.oz (07/26/88)

The book, "Software Engineering Economics' by B.W. Boehm discusses for some
50 pages a software estimating model called COCOMO. I believe some suppliers
have developed programs which provide COCOMO estimates. I have not been
able to find a supplier in Australia who can sell me one. A US supplier
called Sotstar Systems in New Hampshire sells COSTAR which is a PC version.
Perhaps someone on the net can tell me how I might be be able to buy a COCOMO
program.

(I am posting this message on behalf of a friend who has no access to the
net, please mail the response to my address. Thanks.)

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ark@ritcv.UUCP (Alan Kaminsky) (07/29/88)

> The book, "Software Engineering Economics' by B.W. Boehm discusses for some
> 50 pages a software estimating model called COCOMO. I believe some suppliers
> have developed programs which provide COCOMO estimates. I have not been
> able to find a supplier in Australia who can sell me one. A US supplier
> called Sotstar Systems in New Hampshire sells COSTAR which is a PC version.
> Perhaps someone on the net can tell me how I might be be able to buy a COCOMO
> program.

In my opinion, any specialized COCOMO program is a waste of money.  I advise
you to spend your money on a general-purpose spreadsheet program, then take
an hour or so to program the COCOMO model into it.  The resulting "COCOMO
program" will be far more flexible than a specialized program, since you
have all the capabilities of the spreadsheet at your disposal as well as
the COCOMO model.

I have programmed the Intermediate COCOMO model into the Microsoft Excel
spreadsheet for the Apple Macintosh computer.  Excel has extensive business
charting capabilities as well as the usual spreadsheet features.  So my
"COCOMO program" not only gives me the numbers, it gives me a pie chart
showing the breakdown of total effort in each phase, a project profile
graph showing staffing level versus time, and any other graphic depiction
of the numbers I want.

With the spreadsheet, it's also very easy to investigate the effect of
changing one of the model parameters, say, the effect on total effort of
the level of usage of software tools.  Simply copy the spreadsheet formulas
into a new column, and change the software tool usage parameter.  Do this
several times and you have a sensitivity analysis.  You can even display a
graph of total effort vs. software tool usage.

I doubt that many specialized COCOMO programs are as flexible as this.
Also, most specialized COCOMO programs I have seen cost more than spreadsheet
programs.  For calculating a software cost estimation model, a spreadsheet
offers the better value.
-- 
Alan Kaminsky
Rochester Institute of Technology
P. O. Box 9887
Rochester, NY  14623
716-475-5255
ark@cs.rit.edu

yuval@taux02.UUCP (Gideon Yuval) (07/31/88)

In article <569@csdgwy.csd.unsw.oz> ewa@csdgwy.csd.unsw.oz writes:
>Perhaps someone on the net can tell me how I might be be able to buy a COCOMO
>program.

WICOMO (Wang Institute COst MOdel -- a version of COCOMO) 
is available for $70 from:
 Gary Perlman
 617-566-6858
 P.O.Box 1880
 Brookline, Mass, 02146, USA

Gideon Yuval, yuval@taux01.nsc.com, +972-2-690992 (home) ,-52-522255(work)
 Paper-mail: National Semiconductor, 6 Maskit St., Herzliyah, Israel
                                                TWX: 33691, fax: +972-52-558322
             (alternative E-mail address: decwrl!nsc!taux01!yuval@uunet.uu.net)
-- 
Gideon Yuval, yuval@taux01.nsc.com, +972-2-690992 (home) ,-52-522255(work)
 Paper-mail: National Semiconductor, 6 Maskit St., Herzliyah, Israel
                                                TWX: 33691, fax: +972-52-558322
             (alternative E-mail address: decwrl!nsc!taux01!yuval@uunet.uu.net)

vita@daredevil.steinmetz (Mark F. Vita) (08/03/88)

In article <685@ritcv.UUCP> ark@ritcv.UUCP (Alan Kaminsky) writes:
>> Perhaps someone on the net can tell me how I might be be able to buy a COCOMO
>> program.
>
>In my opinion, any specialized COCOMO program is a waste of money.  I advise
>you to spend your money on a general-purpose spreadsheet program, then take
>an hour or so to program the COCOMO model into it.  The resulting "COCOMO
>program" will be far more flexible than a specialized program, since you
>have all the capabilities of the spreadsheet at your disposal as well as
>the COCOMO model.

Yes, you have a point here.  The COCOMO model is not all that
complicated, and it would seem to make good fodder for a spreadsheet
program.  However, this could be said about nearly any numerical
model; i.e. "any specialized XXX program is a waste of money, as you
can just get a spreadsheet and program the XXX model into it."

The key issue, though, I think, is user interface.  In my opinion,
spreadsheets are only slightly above pencil and paper as far as
pleasantness of user interface is concerned.

This may be why, for example, "personal finance" programs for micros
sell so well.  It would be easy enough to come up with a spreadsheet
that would handle all this stuff, figure out your taxes, etc.
However, many people (especially ones who aren't spreadsheet junkies)
prefer dedicated, off-the-shelf programs that have generally have a
much nicer interface, some quick, convenient predefined graphs, nice
reporting features, etc.  For some, the convenience and ease-of-use of
such programs makes them worth the additional expense, despite the
fact that the underlying "model" isn't all that complex.

So I think it may be a bit of an overstatement to assert that "any
specialized COCOMO program is a waste of money."

>Alan Kaminsky
>Rochester Institute of Technology

----
Mark Vita                              ARPA: vita@ge-crd.ARPA
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