From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=ham autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,41100a78496a4c71 X-Google-Attributes: gid103376,public X-Google-Thread: 11232c,3fd68bc06c32b870 X-Google-Attributes: gid11232c,public X-Google-ArrivalTime: 2002-04-07 10:21:02 PST Path: archiver1.google.com!news1.google.com!newsfeed.stanford.edu!news-spur1.maxwell.syr.edu!news.maxwell.syr.edu!news.airnews.net!cabal11.airnews.net!cabal1.airnews.net!news-f.iadfw.net!usenet From: "John R. Strohm" Newsgroups: comp.lang.ada,misc.misc Subject: Re: SLOC-wars Date: Sun, 7 Apr 2002 11:58:46 -0700 Organization: Airnews.net! at Internet America Message-ID: <0D461AE43B9C7272.26672AFB36DC0E75.80298A80A5025686@lp.airnews.net> X-Orig-Message-ID: References: <0b1a7c596d3d0851f6e35f3e81df82bd.48257@mygate.mailgate.org> Abuse-Reports-To: abuse at airmail.net to report improper postings NNTP-Proxy-Relay: library1-aux.airnews.net NNTP-Posting-Time: Sun Apr 7 12:19:27 2002 NNTP-Posting-Host: !XNuq1k-YFa9Qq" (Encoded at Airnews!) X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 5.50.4522.1200 X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4522.1200 Xref: archiver1.google.com comp.lang.ada:22198 misc.misc:6186 Date: 2002-04-07T11:58:46-07:00 List-Id: "Kent Paul Dolan" wrote in message news:0b1a7c596d3d0851f6e35f3e81df82bd.48257@mygate.mailgate.org... > "John R. Strohm" wrote: > > > "Kent Paul Dolan" wrote in message > > >> I'd shudder to think > >> what the accuracy of foresight guesses at SLOC from similar projects > >> might accomplish in setting milestone dates and such. > > > Your shudders would be misplaced. Such estimates are actually pretty good, > > IF you go to the necessary level of detail. Discard your preconceptions and > > read Barry Boehm's "Software Engineering Economics". > > Well, the rest of the story: > > As a contractor at Motorola (IRIDIUM), I watched my Motorola employee > office mate and our common manager very carefully work out an estimate > based on a project of similar complexity done about a year before I > arrived, using the SLOC there as a major basis for the estimate. > > The result? The two level higher-up managers read the estimate workup, > said, "Oh, you've done something like that before!?!" and cut the > furnished estimate in half. > > Not even the best estimating tools and techniques will satisfy a manager > with a preconceived deadline. You're right about that. I've seen a few examples. The key to using COCOMO is explaining how the estimating methodology works, and pointing out how the methodology TAKES INTO ACCOUNT the fact that the team has done something similar in the past. This is the beauty of the COCOMO methodology, once management has bought in to it. The only thing they can argue with is the SLOC estimate, and THAT you have to defend. The effort adjustment factors are all set in stone: the methodology takes certain qualitative criteria into account, and maps them into quantitative adjustments. Once management agrees with you on the SLOC estimate, and agrees with you on the qualitative, they're stuck with the number that falls out when you turn the crank. The other key is to calibrate the methodology to your own organization. This requires you to track a lot of projects at the company, doing SLOC counts, noting the qualitatives, and then doing your own nonlinear regression to fit an estimator. General Dynamics Fort Worth went through that exercise, in detail, and came up with their own COCOMO scale factor and exponent. The key to getting management buy-in on COCOMO is to show them the accuracy that it has historically achieved. COCOMO is damned good, as estimating goes, far better than anything else that was available when it came out. The data is in Boehm's book.