As the developments in engineering production techniques have resulted in an increasing dependence on automation, the increasing complexity of these systems has made the reliability of the machines a matter of great importance. An unexpected breakdown can be a very expensive experience for the company. Further, in the aerospace industry, problems of reliability, maintainability and availability are critical. For a long time industrial research and training centres have been interested primarily in the problems of design, manufacture and production; recently, however, there has been a growing interest in the study of maintenance and reliability. The concept of maintainability, for example, first appeared in 1954 in the US army. Since then a variety of techniques and methodologies have been developed and implemented to meet the challenge of the new needs. The aim of this book is to present these methods and investigate their effectiveness, and in so doing to help practising engineers gain a better understanding of the problems. The many examples and applications given here should make it a valuable teaching aid to students taking courses in engineering maintenance. This second edition has been revised and enlarged to take account of the most recent developments and illustrate their application to the solution of problems. It should also help to orient the reader to the modern concept of computer-aided maintenance. Introduction A maintenance service exists to keep equipment in running order and also to reduce the number of breakdowns.