With aircraft, submarines, military and aerospace systems, it is vital to avoid failure during operation. The study of maintenance policies and models in order to improve system reliability, prevent system failure and reduce maintenance costs is an important area in reliability engineering. Proper maintenance techniques have been emphasized due to increased safety and reliability requirements of systems and increased complexity and rising costs of material and labor. This book presents the latest theories and methods of reliability and maintenance, emphasising multi-component systems. Topics covered include: imperfect repair, economic dependence and opportunistic maintenance, correlated failure and repair, software reliability and maintenance cost, and warranty cost considerations. Postgraduates, researchers and practitioners in reliability, maintenance, industrial or mechanical engineering, operations research, logistics, management and statistics will find this a state-of-the-art survey of the field.