Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!rutgers!bellcore!dduck!duncan
From: duncan@dduck.ctt.bellcore.com (Scott Duncan)
Newsgroups: comp.software-eng
Subject: Re: 50,000 lines: a lot or a little?
Keywords: software engineering economics, code size, Fairley, Yourdon
Message-ID: <17077@bellcore.bellcore.com>
Date: 28 Jun 89 11:14:49 GMT
References: <8587@june.cs.washington.edu>
Sender: news@bellcore.bellcore.com
Reply-To: duncan@ctt.bellcore.com (Scott Duncan)
Lines: 41

In article <8587@june.cs.washington.edu> jon@june.cs.washington.edu (Jon Jacky) writes:
>I just ran across the following table in the textbook, SOFTWARE ENGINEERING
>CONCEPTS, by Richard Fairley, 1985, McGraw-Hill.  It is table 1.1 on p. 11.
>Fairley says he adapted it from Edward Yourdon, TECHNIQUES OF PROGRAM 
>STRUCTURE AND DESIGN, Prentice-Hall, 1975:
>
>	SIZE CATEGORIES FOR SOFTWARE PRODUCTS
>
>Category	N of Programmers	Duration	Size (lines)
>
>Trivial	1			1 - 4 wks	500 
>Small		1			1 - 6 months	1K - 2K
>Medium		2 - 5			1 - 2 years	5K - 50K
>Large		5 - 20			2 - 3 years	50K - 100K
>Very Large	100 - 1000		4 - 5 years	1M
>Extremely large2000 - 5000		5 - 10 years	1M - 10M

I've read both of these books but can't remember the context for these figures.
However, I am struck by the large gap between 100K and 1M as well as by the
number of programmers listed for the two higher categories.

The former is a problem because many of the projects I have looked into are
in that span, taking from 50-100 people.  I cannot imagine why such a gap ex-
ists since it is such a common size for "larger" programs.  The 2-3 year time
limit is about right for this category, I'd say.

The latter is a problem for me since an industry average of lines per person
per year is anywhere from 500 to 7000 based on the kind of application. (This
does NOT count "reused" code and generated code volumes which would drive the
numbers higher for traditional business data processing applications.)  If we
use 3000 LOC/yr as an average, then the number of programmers and years seem
to me to be incredibly large.

Perhaps some aspect of the life-time support and maintenance is being taken
into account here?  Like I said, I do not recall the context of the numbers.
I do believe context is vital whenever such numbers are being discussed!

Speaking only for myself, of course, I am...
Scott P. Duncan (duncan@ctt.bellcore.com OR ...!bellcore!ctt!duncan)
                (Bellcore, 444 Hoes Lane  RRC 1H-210, Piscataway, NJ  08854)
                (201-699-3910 (w)   609-737-2945 (h))