This book grew out of an internal class taught at AT&T Bell Laboratories. The authors also gained experience and insight by testing and refining the book’s ideas on a large number of software projects at AT&T. If offers the best coverage of reliability models and measurement we have seen. Examples and case-study problems are sprinkled liberally throughout, which help the reader understand some of the more theoretical material. The authors state that "although much 'how-to-do-it' information is provided, the value of practically oriented insight is recognized." There has been a conscious effort to avoid theoretical exuberance. The book is nicely indexed so that it can serve as a reference and a glossary of terms. Notations used are provided in the appendix. Another useful appendix contains a summary of all the formulas needed.