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: fac41,b87849933931bc93 X-Google-Attributes: gidfac41,public X-Google-Thread: f43e6,b87849933931bc93 X-Google-Attributes: gidf43e6,public X-Google-Thread: 103376,b87849933931bc93 X-Google-Attributes: gid103376,public X-Google-Thread: 1108a1,b87849933931bc93 X-Google-Attributes: gid1108a1,public X-Google-Thread: 109fba,b87849933931bc93 X-Google-Attributes: gid109fba,public X-Google-Thread: 114809,b87849933931bc93 X-Google-Attributes: gid114809,public From: ell@access1.digex.net (Ell) Subject: Re: What is wrong with OO ? Date: 1997/01/01 Message-ID: <5acfqv$5uj@news3.digex.net>#1/1 X-Deja-AN: 207032988 organization: The Universe followup-to: comp.lang.c++,comp.lang.smalltalk,comp.lang.eiffel,comp.lang.ada,comp.object,comp.software-eng newsgroups: comp.lang.c++,comp.lang.smalltalk,comp.lang.eiffel,comp.lang.ada,comp.object,comp.software-eng Date: 1997-01-01T00:00:00+00:00 List-Id: Nigel Tzeng (nigel@access4.digex.net) wrote: : In article <5a9r1k$e74@news4.digex.net>, Ell wrote: : : [snip] : : >Because Boeing had a super diagram doesn't mean it's highest level was : >predicated on a single, or even specific set of, technology, i.e. on one : >or more specific languages, or distribution technologies in our case. : 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 one technology or the other. I would leave it to lower levels to figure out how to meet the weight goal. If the lower levels found the goal impossible they would give feedback to the top level and we would make the requisite changes to the top level. So my approach, rather than squeezing out or constraining the implementors, in fact gives them greater lattitude. If we had determined at the top level what the technology was to be, we would have restricted options both at the top and at lower levels. If you haven't already you might check out Constantine's end column in this or last month's Object magazine. He talks about the goodness of "delaying" implementation decisions as long as possible. Elliott