Date: Sun, 09 Apr 1995 18:17:10 EST From: "Rob Slade, Social Convener to the Net" Subject: "Metrics and Models in Software Quality Engineering" by Kan BKMAMSQE.RVW 940221 "Metrics and Models in Software Quality Engineering", Kan, 1995, 0-201-63339-6, U$39.75 %A Stephen Kan %C 1 Jacob Way, Reading, MA 01867-9984 %D 1995 %G 0-201-63339-6 %I Addison-Wesley %O U$39.75 800-822-6339 617-944-3700 Fax: (617) 944-7273 %P 344 %T "Metrics and Models in Software Quality Engineering" This is an introduction to quality enhancement methods and measurements. It is broadly based, but also gives depth to the discussion in many areas. Areas such as the definition of quality and statistical modelling, which may be new to software developers and managers, start from simple and clearly explained concepts. Chapters cover the definition of quality development and quality management models, measurement theory, software quality measures (metrics), quality identification tools, defect removal, the Rayleigh model and expectation of defects, exponential models for expectations, the use of Rayleigh and other models in management, complexity, and customer satisfaction measurement. There is very thorough bibliographic material at the end of each chapter. The quality of this work, in one sense, is beyond question. In terms of the book's own definition of "fitness for use," however, there are some points to be raised. Software, as we all know, is digital. It is subject to catastrophic failures which cannot be predicted by statistical models of "errors per thousand lines of code". The need for customer input is repeatedly stressed. The Patriot missile system failure, mentioned in the book, was based on a customer requirement for a maximum fourteen-hour run time. Customer specifications, obviously, required an error recall function for the Therac 25. Unfortunately, neither the customer nor the company thought it necessary to have a final check display of the parameters taken by the machine, assuming the recall would work in all cases. Mention is made of "object orientation" and the reuse of software. It was reuse of an object, valid in its own environment, which led to the Pentium fiasco. Finally, there is the *cost* of quality, pointed out in "Four Days With Dr. Deming" (cf. BKDEMING.RVW). Kan's work, voluminous as it may be, is only an introduction. Thus, it would be primarily of use in a very large effort where the project manager had technical and statistical assistance simply for project management. As an example, I give you the Internet. The "quality standard" of "rough consensus and running code" must make quality specialists shudder. Without it, however, we'd be looking at a network based on OSI. (No sniggering >from you UDP hackers in the back, there.) copyright Robert M. Slade, 1995 BKMAMSQE.RVW 950221 ============== Vancouver ROBERTS@decus.ca | "90% of infections Institute for Robert_Slade@sfu.ca | are Stoned." Research into Rob_Slade@mindlink.bc.ca | User Rob.Slade@f733.n153.z1.fidonet.org| - the viral corollary Security Canada V7K 2G6 | to Sturgeon's Law