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=-1.3 required=5.0 tests=BAYES_00,INVALID_MSGID autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 109fba,b87849933931bc93 X-Google-Attributes: gid109fba,public X-Google-Thread: fac41,b87849933931bc93 X-Google-Attributes: gidfac41,public X-Google-Thread: 1108a1,b87849933931bc93 X-Google-Attributes: gid1108a1,public X-Google-Thread: 114809,b87849933931bc93 X-Google-Attributes: gid114809,public X-Google-Thread: f43e6,b87849933931bc93 X-Google-Attributes: gidf43e6,public X-Google-Thread: 103376,b87849933931bc93 X-Google-Attributes: gid103376,public From: Paul Eric Menchen Subject: Re: What is wrong with OO ? Date: 1997/01/08 Message-ID: <32D41F93.327B@grci.com>#1/1 X-Deja-AN: 208705119 references: <5acfqv$5uj@news3.digex.net> to: Ell content-type: text/plain; charset=us-ascii organization: GRC International, Inc. mime-version: 1.0 reply-to: emenchen@grci.com newsgroups: comp.lang.c++,comp.lang.smalltalk,comp.lang.eiffel,comp.lang.ada,comp.object,comp.software-eng x-mailer: Mozilla 3.01Gold (Win95; I) Date: 1997-01-08T00:00:00+00:00 List-Id: Ell wrote: > > Nigel Tzeng (nigel@access4.digex.net) wrote: > : In article <5a9r1k$e74@news4.digex.net>, Ell wrote: ... > : Actually I think that one can make the case that the highest level was > : predicated on a specific set of technology. I'm going to speculate a > : little here since I know virtually nothing about the actual 777 design > : but here goes: > : > : Say they started with a specific weight goal for the airframe or they > : couldn't get the performance they wanted out of the aircraft. They > : thought they could meet this goal through the use of composites. The > : choice of composites then bounds the high level airframe architecture > : because of what you can and cannot do with composites (compare to say > : conventional airframes made of metal). > > I think we see the top level design in different ways. I see it as a > logical thing with no commitment to a technology. In the above you are > positing the use of "composites" up front. My top level design would only > incorporate the desire to meet a specific weight goal without commiting to What is the top level? Why should the requirement be a weight goal? You've already precluded solutions. If my design weighs twice as much as your weight goal, but uses half as much fuel, shouldn't it be allowed (presuming I've also handled other situations where weight might be an issue)? In one way, the real requirement is one of operational cost. Is the requirement to move people at a given cost? Then my Star Trek transporter design shouldn't be precluded. Reality is we have to start somewhere. Leave things too open, and you'll discover requirements down the road you hadn't thought of; too closed and you preclude solutions. Sometimes you may be wrong. Hopefully the designer is smart and brave enough to point this out to you. -Eric -- /----------------------------------------- / /| /| Paul Eric Menchen /---- / | / | emenchen@grci.com / / |/ | http://www.nicom.com/~zelkova <- soon! /--------------------------------------------- The opinions expressed herein are strictly those of the author and do not necessarily reflect those of GRCI.