Experts in operations research and developers of software application systems have been treading separate paths for many years. It is urgently necessary to reset this course so that the demanding requirements of various CIM concepts can be realized. This is especially relevant for computer-based stock management. The authors, with a number of years of practical experience behind them, have written this book with this objective in mind. The book shows how modern inventory control can be rationally structured with the help of OR. The necessary mathematical derivations are explained in detail so that the reader will be able to handle a given situation optimally with the help of the methods learned. Aside from the models, strong emphasis is placed on numerical methods. Suitable algorithms are thoroughly explained for the more important cases.