Abstract: Distribution of the parts (parts A, parts B), including shipment by a part supplier, delivery to the part orderer to be used in product manufacturing, is divided into stages in time-sequence (under transportation or at a location including the parking lot, warehouse, temporary storage facility, line side, etc.) and each stage is inputted with incoming and outgoing quantity information of the part orderer to compute the quantity of inventory from a difference therebetween. Information on the computed quantity of inventory is sent through terminal computers to a host computer such that it consolidates the sent information to be centralized and manages at a lump. Further, among of the quantities of inventory at divided stages, the quantity of inventory computed based on the incoming and outgoing quantity information of the part orderer is recognized as the actual quantity of inventory.

Abstract: There are provided with an order quantity computing technique (S16, S18) that computes a relatively short-term part order quantity based on the actual quantity of the parts so as to decrease the quantity of inventory and to achieve a stable part supply, and an order quantity computing technique (S22, S24) that computes a relatively long-term order quantity based on the tentative quantity of inventory of the parts (a quantity of inventory computed based on the past production records) so as to obtain mass production effects such that one of them is selected to be used by comparing the price of the parts with the prescribed price (S14). With this, it becomes possible to easily change the part order quantity computation technique in response to the lead time of the parts, thereby enabling to effectively utilize the advantages of two different part order quantity computation techniques.