We are very pleased to be asked to co-author this book for a variety of reasons, one of which was that it gave us further opportunity to work together. The scope proposed was very wide with the only significant proviso being that the book should be in a mongraph-style and not a teaching text. This require ment has given us the opportunity to compile a wide range of relevant material relating to present-day knowledge and application in power system reliability. As many readers will be aware, we have collaborated in many ways over a relatively long period and have co-authored two other books on...