Despite the widespread use of computer based inventory control systems, most companies are aware that they often cannot meet their customer demand, while still suspecting that their stock levels are higher than they should be. The main reason for this problem is that many of the managers responsible for inventory control have no clear idea of what level of service they should be expecting to achieve on the basis of any given level of inventory, or how they should go about improving their performance. This guide sets out to help managers think through their inventory control operations, set goals which are realistic for their particular business and understand the limitations of even the most sophisticated systems.