Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!uwm.edu!uakari.primate.wisc.edu!uflorida!gatech!udel!rochester!rit!mjl From: mjl@cs.rit.edu Newsgroups: comp.software-eng Subject: Re: The Errors of TEX Keywords: testing debugging structured-programming OOD Message-ID: <1344@cs.rit.edu> Date: 12 Oct 89 21:53:32 GMT References: <2402@munnari.oz.au> Sender: news@cs.rit.edu Reply-To: mjl@prague.UUCP (Michael Lutz) Organization: Rochester Institute of Technology, Rochester, NY Lines: 37 In article <2402@munnari.oz.au> sharam@munnari.oz.au (Sharam Hekmatpour) writes: [Comments about Don Knuth's version of Big Bang testing the whole TEX program at the end.] >The worst aspect of Big Bang is that it gives you no time to reconsider >your design. When it comes to testing, a whole army of design faults hit >you dead. You'll have no idea where to begin. The bugs are so many and >so interdependent that you don't know what's causing what. From this point >on it's all hacking. This is where false confidence gets you. > At the risk of oversimplification, this "Big Bang" approach has been packaged by Harlan Mills, et. al., under the name of Clean Room Software Engineering. Software products are never tested, or even compiled, by the designers and implementers; instead, these folks spend their time on rigorous verification of the design and implementation. Testing is done, but by a separate group, and with the goal being reliability prediction and statistical quality control rather than defect detection and removal. The claim is that large software systems with defect rates way below industrial average have been developed this way. But it does require a rigorous approach, and of course testing is still performed. Reference: "Cleanroom Software Engineering", Mills, Dyer, and Linger, IEEE Software, September 1987. > >+--- >| Sharam Hekmatpour | > Melbourne University ---+ Mike Lutz Rochester Institute of Technology, Rochester NY UUCP: {rutgers,cornell}!rochester!ritcv!mjl CSNET: mjl%rit@relay.cs.net INTERNET: mjl@cs.rit.edu