Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!bu.edu!m2c!jjmhome!smds!rh From: rh@smds.UUCP (Richard Harter) Newsgroups: comp.software-eng Subject: Re: COCOMO Summary: Sorry Jim, I just don't believe it. Message-ID: <568@smds.UUCP> Date: 19 Jun 91 05:22:37 GMT References: <1991Jun18.033606.1362@netcom.COM> Distribution: comp Organization: SMDS Inc., Concord, MA Lines: 46 In article <1991Jun18.033606.1362@netcom.COM>, jls@netcom.COM (Jim Showalter) writes: > >(1) Empirically, in any organization, man-months per 1000 lines of code > >(K SLOC) is roughly constant, no matter what language or environment is > >used. So, we can always assume that effort in man-months is > >proportional to size in KSLOC. > The primary complaint I and others have with the COCOMO model is the > above claim. To assert that a person writing in some homebrew > dialect of FORTRAN using a line editor on an IBM mainframe with a circa 1962 > debugger is as productive (or even within two orders of magnitude as > productive) as a person using the latest-greatest software development > environment and one of the modern software engineering oriented languages > (e.g. Ada, Eiffel, C++, etc) is prima-facie absurd, claims of empiricism > notwithstanding. Sorry Jim, I just don't believe it. I was programming in 1962 -- using punched cards (how many people were actually using line editors and terminals in those days?) Modern tools make a difference, but nothing like what you claim -- I will grant you a factor of three, no more. In ye olde days you worked the code all out before you keypunched it, listed it after keypunching, desk checked it, and made the revisions before ever compiling. The old way of working from a listing had its advantages; the window of visibility for a listing was greater than that of a terminal screen. My personal observation is that I could crank out about 20,000 lines of production code per year then, and I do about the same now. The language (almost) doesn't matter. Nor is this surprising. Writers (you know, people who write books) all use fancy word processors these days, but they don't, on average, produce that much more than they did with manual typewriters. There is a good reason for this. The amount of thought, of intellectual effort, and the time that it takes for that intellectual effort is the controlling factor. The tools make the physical effort easier and more pleasant. They make certain mechanical tasks (spell checking for the writer) faster and more reliable. On the other hand I will grant you that modern software and hardware technology does mean that you can do more in the same number of lines of code, and that it is much easier to build large programs. One further side note: Debuggers, no matter how good, are the symptom of a disorderly approach to software development. -- Richard Harter, Software Maintenance and Development Systems, Inc. Net address: jjmhome!smds!rh Phone: 508-369-7398 US Mail: SMDS Inc., PO Box 555, Concord MA 01742 This sentence no verb. This sentence short. This signature done.