This book aims to present a state-of-the-art survey of theories and methods of reliability, maintenance, and warranty with emphasis on multi-unit systems, and to reflect current hot topics: imperfect maintenance, economic dependence, opportunistic maintenance, quasi-renewal processes, warranty with maintenance and economic dependency, and software testing and maintenance. This book is distinct from others because it consists mainly of research work published on technical journals and conferences in recent years by us and our co-authors. Maintenance involves preventive and unplanned actions...