Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!elroy.jpl.nasa.gov!decwrl!netcomsv!jls From: jls@netcom.COM (Jim Showalter) Newsgroups: comp.software-eng Subject: Re: COCOMO Message-ID: <1991Jun18.214011.17765@netcom.COM> Date: 18 Jun 91 21:40:11 GMT References: <677047335@macbeth.cs.duke.edu> <1991Jun18.033606.1362@netcom.COM> <677256043@macbeth.cs.duke.edu> Distribution: comp Organization: Netcom - Online Communication Services UNIX System {408 241-9760 guest} Lines: 63 crm@duke.cs.duke.edu (Charlie Martin) 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. [I respond that this is absurd, to which Mr. Martin responds:] >I always hate it when someone says something is "prima facie absurd" >like this. First of all, notice the claim is not *everyone*, but that >*within an organization* the productivity is roughly constant. I think I see the problem here. I'm probably not parsing your statement the way you are writing it. When I read the original post, it seems to read--to my parser at least--as follows: "It doesn't make any difference what language or environment your organization uses, because you'll always produce the same amount of code in the same amount of time, regardless". This was the statement I was claiming was absurd, because, of course, it IS (is there anybody out there who thinks this statement is NOT absurd?). In your followup response, you rephrase things so that I get the idea you are actually saying something else entirely, in which case we probably aren't arguing, just failing to communicate. >But secondly, "claims of empiricism" cannot be just unceremoniously >dumped. The fact is that this relationship held over something like 400 >projects, in dozens of different environments, with languages from >assembler to the best HLL's of the time. Where is your counter >evidence? How was it measured? I've witnessed organizations producing code at anywhere from 5 lines per week per programmer to about five hundred lines per week per programmer, which is a three order of magnitude spread. But since I'm not sure what your original claim was, I'm not sure if this refutes it or is completely unrelated to it. >and we can see that at some point the effects of increasing size >dominate the effects of anything that affects just the constant (so long >as d > 1.) One supposition I've made is that the difference between >programming-in-the-small and programming-in-the-large is that large >scale programming is when scale dominates in this equation. >[ This is my Discovery Of the Week. I can't decide if I think it's >significant or not.] I agree that this is a good Discovery of the Week, and it is the fact that we so strongly agree here that leads me to believe that we probably agree on the earlier stuff too, if we can just get our communications ungarbled. >You didn't read down far enough. The relation has not one but two >factors that can be set or chosen to suit differences in the >environment. In the Intermediate and Advanced COCOMO models there are a >number of factors that model things like language chosen, environment, >use of a methodology, etc. Basic COCOMO does not take these into >account, and as you say is inherently inaccurate. Ah, see, then we DO agree. So much for this thread... -- *** LIMITLESS SOFTWARE, Inc: Jim Showalter, jls@netcom.com, (408) 243-0630 **** *Proven solutions to software problems. Consulting and training on all aspects* *of software development. Management/process/methodology. Architecture/design/* *reuse. Quality/productivity. Risk reduction. EFFECTIVE OO usage. Ada/C++. *