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,f039470e8f537101 X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2003-07-28 17:41:35 PST Path: archiver1.google.com!postnews1.google.com!not-for-mail From: aek@vib.usr.pu.ru (Alexander Kopilovitch) Newsgroups: comp.lang.ada Subject: Re: Ariane5 FAQ Date: 28 Jul 2003 17:41:35 -0700 Organization: http://groups.google.com/ Message-ID: References: <1058968422.225561@master.nyc.kbcfp.com> <3F200AD0.94F79098@adaworks.com> <7u9Ua.13412$634.10307@nwrdny03.gnilink.net> <3F215120.1040706@attbi.com> <1059151910.357790@master.nyc.kbcfp.com> <3F248CEE.5050709@attbi.com> NNTP-Posting-Host: 62.152.82.55 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit X-Trace: posting.google.com 1059439295 23108 127.0.0.1 (29 Jul 2003 00:41:35 GMT) X-Complaints-To: groups-abuse@google.com NNTP-Posting-Date: 29 Jul 2003 00:41:35 GMT Xref: archiver1.google.com comp.lang.ada:40917 Date: 2003-07-29T00:41:35+00:00 List-Id: Robert I. Eachus wrote: >The programmers simulating the SRI for the flight guidance >simulator did not see the alignment function code--because simulating it >was not part of their contract. This is very serious and interesting allegation. Are you sure of that fact, or it is just good guess? I'm not asking for a reference, just say that you *know* that this is true fact. I think that this fact deserves particular attention also because, if true, it means that somebody knew in advance about the differences between Ariane 4 and Ariane 5 relative to SRI software functionality, and specifically excludes from the contract the part, which is irrelevant to Ariane 5. So, they did not ask for simulation of the SRI as a whole, naively thinking that there should be no differences -- on the contrary, they *knew* that there is significant difference and deliberately ordered to exclude from simulation the part, which deals with that difference. >Of course, if anyone involved in letting that contract had known that >the alignment function on the Ariane 4 was required to run for 40 >seconds after engine start, simulation of it might have been included in >the simulator. Or something else might have happened that resulted in >an engineer learing of this requirements mismatch. Just after the above two paragraphs I understand, at last, all the meaning of those unfortunate 40 seconds. Yes, you told about that earlier, and perhaps several times, but still it did not seem essential -- until you said that this part was deliberately excluded from the simulator at the contract level. >But as we know, no one was ever in a position to do a diff between the >Ariane 4 and Ariane 5 requirements, and then apply that to reused >subsystems. No, this contradicts (although indirectly) your previous statement. How can one exclude anything from the simulator's contract if nobody can see differences between the Ariane 4 and Ariane 5? Alexander Kopilovitch aek@vib.usr.pu.ru Saint-Petersburg Russia