Level-by-level explosion method for material requirements planning

Abstract

Upon starting of MRP processing, material information and product structure stored on a disk are extracted into a material information table and a product structure table, respectively, and the two tables are related with each other such that upon one level explosion in MRP, explosion to lower items can be performed only by designation of an address without retrieving component parts from a parent part. Further, a calendar day table and an operating day table are used to produce a composite calendar table. The composite calendar table is used for important date calculations. Moreover, upon registration into a key area of a management table of demand information contents at a plurality of positions of the key area are replaced with each other. And, upon extraction of the demand information from the management table, contents at a plurality of positions of the key area are replaced with each other. Consequently, upon ordering processing, the demand information can be extracted in a sorted order from the management table in a very short time.