For some systems, such as aircraft, submarines, military systems and aerospace systems, it is extremely important to avoid failure during actual operation because it is dangerous and disastrous. The study of various maintenance policies and models in order to improve system reliability, to prevent the occurrence of system failure, and to reduce maintenance costs is an important area in reliability engineering. Proper maintenance techniques have been emphasized in recent years due to the increased safety and reliability requirements of systems, and the increased complexity and rising costs of material and labor. Based on the authors’ research, Reliability and Optimal Maintenance presents the latest theories and methods of reliability and maintenance with an emphasis on multi-component systems, while also considering the current hot topics in reliability and maintenance including: imperfect repair, economic dependence and opportunistic maintenance, and correlated failure and repair. Software reliability and maintenance cost, and warranty cost considerations are also considered. Postgraduates, researchers, and practitioners in reliability engineering, maintenance engineering, operations research, industrial engineering, mechanical engineering, logistics, management, and statistics will find this book a state-of-the-art survey of reliability and maintenance theory and models. Springer Series in Reliability Engineering publishes high-quality books in important areas of current theoretical research and development in reliability, and in areas that bridge the gap between theory and application in areas of interest to practitioners in industry, laboratories, business, and government.