Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!swrinde!ucsd!mvb.saic.com!eafbvax!eafbtems!martin From: martin@edwards-tems.af.mil Newsgroups: comp.software-eng Subject: Re: Provocative statement Message-ID: <1991May7.130115.55@edwards-tems.af.mil> Date: 7 May 91 20:01:15 GMT References: <9776@castle.ed.ac.uk> <1991Apr25.133216.20855@jyu.fi> <1991May3.195844.25823@dg-rtp.dg.com> <34081@mimsy.umd.edu> Organization: T&E Mission Simulator - Edwards AFB, CA Lines: 28 In article <34081@mimsy.umd.edu>, straub@jogger.cs.umd.edu (Pablo A. Straub) writes: > > Yes, you can engineer software robustness. But let's not stretch the > analogy to far. Software is still not continuous and robustness is not > achieved by adding more of the same. As Jim Showalter explained to us, > program robustness is achieved by changing the design, not just adding > more code. > Neither continuity nor linearity are universally present in physical systems. You are just as likely to make any complex physical structure (e.g. a bridge) weaker as you are stronger by adding "more of the same". I can guarantee you that a fiberglass airplane will be made weaker by adding a "little" extra resin on each layer of cloth (Burt Rutan has repeatedly proven this). If you want to make it stronger than its original design strength, you must redesign it. There is no difference between software and hardware when it comes to engineering in robustness. Sometimes it is a linear process (providing larger buffers and arrays than you could possibly envision anyone ever using) and sometimes it isn't. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Gary S. Martin ! (805)277-4509 DSN 527-4509 6510th Test Wing/TSWS ! Martin@Edwards-TEMS.af.mil Edwards AFB, CA 93523-5000 ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -