Tools for measuring software reliability

The author discusses a measure of software reliability and various models for characterizing it, the result of 15 years of theoretical research and experimental application, which are moving into practice and starting to pay off. These tools let developers quantify reliability, give them ways to predict how reliability will vary as testing progresses, and help them use that information to decide when to release software. He examines the distinction between failures and faults and how these affect reliability. He compares execution-time models with calendar-time models, which are less effective, and discusses the choice of execution-time models. The author then describes a generic, step-by-step procedure to guide software reliability engineers in using the reliability models.<>