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=0.2 required=5.0 tests=BAYES_00,INVALID_MSGID, REPLYTO_WITHOUT_TO_CC autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: fac41,2c6139ce13be9980 X-Google-Attributes: gidfac41,public X-Google-Thread: f43e6,2c6139ce13be9980 X-Google-Attributes: gidf43e6,public X-Google-Thread: 103376,3d3f20d31be1c33a X-Google-Attributes: gid103376,public X-Google-Thread: 1108a1,2c6139ce13be9980 X-Google-Attributes: gid1108a1,public From: Ken Garlington Subject: Re: Safety-critical development in Ada and Eiffel Date: 1997/08/23 Message-ID: <33FFB7C8.460E@flash.net>#1/1 X-Deja-AN: 268282850 References: <33faf0d7.732095@wizard.pn.com> Organization: Flashnet Communications, http://www.flash.net Reply-To: Ken.Garlington@computer.org Newsgroups: comp.object,comp.software-eng,comp.lang.ada,comp.lang.eiffel Date: 1997-08-23T00:00:00+00:00 List-Id: > Having said that, it's also true that verifiable specifications *do* get omitted > from specifications, not because it's impossible to specify them, but because > they're difficult to specify. Although some are unlikely to admit it, the Ariane > profile thingo probably falls into that category. Total nonsense. Flight envelopes can easily be specified, and usually are. They can also be tested. Read the inquiry report: The profile "thingo" was left out not because it was hard to specify, but because it (and the corresponding validation) was thought to be _unnecessary_, since the system was already in operation. What would be difficult would be to write an assertion to capture the flight envelope. This would require a model of the environment inside the code. Such a model can be created in a laboratory and used to validate a system, but it is difficult (not impossible, but difficult) to build it into the system itself. > > Don. > =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- > Don Harrison donh@syd.csa.com.au