PROBLEM TO BE SOLVED: To provide a production planning method for adjusting to minimum inventory without waste within a range of not running out of stock. SOLUTION: This production planning method comprises the following means (1)-(6). (1) Reference lot sizes are set for every brand. (2) A first reference inventory amount which is the total of demand amounts for a replenishment period corresponding to a production planning object period, and a second reference inventory amount which is the total of demand amounts for a replenishment period corresponding to a period from planning of a production plan to the termination of a stop period of a plant, are set. (3) The remainders of received orders on order-received products are computed for every brand. (4) Lots whose degrees of allowance are a preset upper limit value or less are extracted. (5) The lots are extracted until the total of production demand amounts reaches a producible amount or more in the production planning object period. (6) A production schedule for producing the extracted lots is determined. COPYRIGHT: (C)2005,JPO&NCIPI
