This book studies storage policies in warehousing systems and maintenance-support strategies for critical operational systems in warehouses, which are the most important issues affecting operational efficiency of warehousing systems. It expands on the theory of class-based storage by considering a finite number of items in store, and also introduces the maintenance-support strategy founded on performance-based contract theory. It is a valuable resource for researchers, practitioners and engineers in the fields of industrial engineering, operations management, operations research and management science.