Handbook of Software Reliability Engineering


Foreword by Richard A. DeMillo, Purdue University and Bellcore

Early in this exhaustive treatment of what may be the single most critical aspect of modern software development, the editor says "Mature engineering fields classify and organize proven solutions in handbooks so that most engineers can consistently handle complicated but routine designs." The reliability engineering of software has become mature with the appearance of this Handbook.

In my graduate software engineering course, I motivate the importance of early test planning with reliability requirement setting examples. It is, in my experience, an issue about which success or failure of major systems projects revolve. In the early 1980s I led the DOD's software testing and reliability analysis team for the final operational tests of the now-famous Patriot Missile System. The questions? What was the required system reliability? Was the operational test data consistent with these requirements? Not many people know how close Patriot came to being rejected as a viable weapons system---not because the system itself was bad, but rather because the reliability engineering was so flawed that developers could not determine how reliable it really was. This crisis could have been avoided had software reliability engineering practice been systematized and applied in the manner advocated by this Handbook.

Reliability theory and engineering statistics textbooks ignore software, for the most part. Software engineering textbooks generally ignore reliability theory. Classroom teachers of the subject are forced to the kind of anecdotal material mentioned above, perhaps augmented by special-purpose supplementary readings. Even worse, software reliability theory has a reputation for facileness that has been encouraged by the many contributors who try to apply hardware reliability models mutatis mutandis to the very different (and more difficult) problems of software reliability.

So, when I was asked by the editor to review this Handbook, I agreed eagerly. On the one hand, a "real" handbook would be of inestimable help to practitioners, decision makers, teachers, and students. On the other hand, a spotty or imbalanced treatment would only make matters worse. I said I would offer my comments only after reading the entire book.

The first thing I did when I received the manuscript was to check it against my classroom "staples." There for the first time in book form was a coherent approach to developing reliability requirements. There also was a discussion of the relationship between software test and reliability estimation, the impact of software architecture on reliability, error studies and software fault classification, tools and methods extracted from best-practice benchmarks of the best reliability labs in the world, actual data. It was all there---and in pretty much the same form in which I would have presented it myself. The editor even included exercises to make it suitable for classroom use.

Encouraged, I read the manuscript front to back. This is a book that will be the standard by which the field is measured for years to come. It is thorough, correct, readable, and so current that it actually anticipates results that have not appeared in archival journals yet. It contains the best work of many of the founders of the field. It contains innovations by some of the rising stars. It is, however, more than anything else a Handbook in the tradition of the classic handbooks of mathematics, physics, and engineering. It does not present software reliability as a silver bullet. It does not attempt to proscribe the complex system usages that would required skill and training on the part of software developers. Rather it seeks to "...classify and organize proven solutions...so that most engineers can consistently handle complicated but routine designs." In this it succeeds, far beyond my expectations. It clearly establishes software reliability engineering as a mature engineering discipline.

Richard A. DeMillo
Morristown, New Jersey