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: 103376,3141f12a6a7d0751 X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2002-01-09 13:47:03 PST Path: archiver1.google.com!news1.google.com!newsfeed.stanford.edu!news-spur1.maxwell.syr.edu!news.maxwell.syr.edu!cpk-news-hub1.bbnplanet.com!news.gtei.net!newscon02.news.prodigy.com!newsmst01.news.prodigy.com!prodigy.com!postmaster.news.prodigy.com!newssvr12.news.prodigy.com.POSTED!not-for-mail From: "Pat Rogers" Newsgroups: comp.lang.ada References: <3c3aea7b$1@pull.gecm.com> <6fD_7.8548$cD4.15360@www.newsranger.com> <3C3CB31E.BC6FDBED@acm.org> Subject: Re: ANNOUNCE: Ada success story in IEEE Software X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 6.00.2600.0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 Message-ID: NNTP-Posting-Host: 208.191.180.40 X-Complaints-To: abuse@prodigy.net X-Trace: newssvr12.news.prodigy.com 1010612789 ST000 208.191.180.40 (Wed, 09 Jan 2002 16:46:29 EST) NNTP-Posting-Date: Wed, 09 Jan 2002 16:46:29 EST Organization: Prodigy Internet http://www.prodigy.com X-UserInfo1: TSU[@IONFJVMQVPXJZDBNFXBBZ\LPCXLLBWLOOAFMASJETAANVW[AKWZE\]^XQWIGNE_[EBL@^_\^JOCQ^RSNVLGTFTKHTXHHP[NB\_C@\SD@EP_[KCXX__AGDDEKGFNB\ZOKLRNCY_CGG[RHT_UN@C_BSY\G__IJIX_PLSA[CCFAULEY\FL\VLGANTQQ]FN Date: Wed, 09 Jan 2002 21:46:29 GMT Xref: archiver1.google.com comp.lang.ada:18713 Date: 2002-01-09T21:46:29+00:00 List-Id: "Jeffrey Carter" wrote in message news:3C3CB31E.BC6FDBED@acm.org... > Ted Dennison wrote: > > > > In article <3c3aea7b$1@pull.gecm.com>, Martin Dowie says... > > > > > >"Dale Stanbrough" wrote in message > > >news:dstanbro-FFA1D2.23113708012002@mec2.bigpond.net.au... > > >> Rod Chapman wrote: > > >> > > >> > factor in the success of the project. The final system achieved > > >> > 0.04 defects per kloc (that's 4 defects in 100,000 lines of code) post- > > >> > delivery, which compares favourably with industry norms. > > >> > > >> I'm not sure I follow this. If this result is the industry norm, > > .. > > >He said it "compares favourably with industry norms" not "matches the > > >industry norms" > > > > I suspect that may have been a bit of that famous British understatement too. I > > think our last (non safety-critical) Ada project would have had a defect count > > orders of magnitude higher than that. > > I recall seeing the "industry norm" given as 1 defect per kloc. In a study described in a paper published in 1986, Herbert and Myron Hecht found that for each million lines of code, 20,000 bugs existed. Normally 90% would be found by testing. Another 200 would be found during the first year of operation by users, leaving 18,000 undetected bugs. Regular maintenance would fix 200 bugs, but also introduce 200 new ones. Things have probably progressed *a little* since then, but not much; certainly not orders of magnitude. Too, that's just one study (of several large systems), but the magnitude is astounding. (Both individuals are extremely well respected in the software fault tolerance field.) The paper is: H. Hecht and M. Hecht, "Software Reliability In The Systems Context," IEEE Transactions On Software Engineering, vol. 12, no. 1, pp. 51-58, 1986. --- Patrick Rogers Consulting and Training in: http://www.classwide.com Real-Time/OO Languages progers@classwide.com Hard Deadline Schedulability Analysis (281)648-3165 Software Fault Tolerance