Information Systems for Observing Inventory Levels

This paper analyzes some problems in the design of information systems for observing and reporting inventory levels. The designer has simultaneously to choose a system for observing inventory and a method for incorporating the information obtained into an estimate of inventory levels. With regard to the observation system the designer can choose to use “physical stocktaking” or the “perpetual inventory” method in any period. With regard to the estimation system the designer can choose to use the observations themselves in forming the estimates of the inventory level (conventional system), or he can process the observations to form estimates of inventory levels that are optimal in a least-squares sense. We develop techniques for information system design and provide numerical examples.