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=1.2 required=5.0 tests=BAYES_00,FROM_WORDY, INVALID_MSGID autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: fac41,e01bd86884246855 X-Google-Attributes: gidfac41,public X-Google-Thread: 103376,fb1663c3ca80b502 X-Google-Attributes: gid103376,public From: "Ken Garlington" Subject: Re: Interesting thread in comp.lang.eiffel Date: 2000/07/19 Message-ID: #1/1 X-Deja-AN: 648031052 References: <8ipvnj$inc$1@wanadoo.fr> <8j67p8$afd$1@nnrp1.deja.com> <395886DA.CCE008D2@deepthought.com.au> <3958B07B.18A5BB8C@acm.com> <395A0ECA.940560D1@acm.com> <8jd4bb$na7$1@toralf.uib.no> <8jfabb$1d8$1@nnrp1.deja.com> <8jhq0m$30u5$1@toralf.uib.no> <8jt4j7$19hpk$1@ID-9852.news.cis.dfn.de> <3963CDDE.3E8FB644@earthlink.net> <3963DEBF.79C40BF1@eiffel.com> <396502D2.BD8A42E7@earthlink.net> <39654639.B3760EF2@eiffel.com> X-Priority: 3 X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2919.6600 X-Complaints-To: abuse@flash.net X-Trace: news.flash.net 963972984 216.215.70.60 (Tue, 18 Jul 2000 21:16:24 CDT) Organization: FlashNet Communications, http://www.flash.net X-MSMail-Priority: Normal NNTP-Posting-Date: Tue, 18 Jul 2000 21:16:24 CDT Newsgroups: comp.lang.ada,comp.lang.eiffel Date: 2000-07-19T00:00:00+00:00 List-Id: "Veli-Pekka Nousiainen" wrote in message news:vnZc5.210$2y3.8676@read2.inet.fi... > What if I'm _designing_ a new control computer (Endaira v.4 -> v.5) > and a new software for it. Maybe I want the contracts from > the earlier HW/SW builders and some test material? Certainly. Sextant had both, and used both (since they *were* the original builders). > Here we go again: You think I would have used that old > test material right away, don't you? No, you probably would have compared it against your revised requirements. And, as in the Ariane 5 case, if your requirements had a hole in them (but were internally consistent), you probably would have ended up with a poor validation test (as did Ariane 5). Then, if your software was never tested by someone who had the information that would have filled that hole, they obviously wouldn't have caught the problem (as in the case of Ariane 5). Then, if your software were put in the system where the hole WAS filled (because it's the real system!), and the system executed, it quite possibly would find the hole (as did Ariane 5 -- with catastrophic results)! As a simple example -- determine if the implementation below meets the requirement: -- Requirement: Set the variable to the value 100 X := 100;