PROBLEM TO BE SOLVED: To provide a production planning method for adjusting inventory to the minimum without waste within a range of not running out of stock. SOLUTION: This production planning method comprises the following means (1)-(5). (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 planning of a production plan to the termination of a stop period of a plant, are set. (3) In order from a lot with a small degree of allowance, lots are extracted until the accumulating total of the reference lot sizes of the brands constituting the extracted lots reaches a producible amount or more in the production planning object period. (4) The lots are extracted until the total of production demand amounts reaches the producible amount or more in the production planning object period. (5) A production schedule for producing the extracted lots is determined. COPYRIGHT: (C)2005,JPO&NCIPI
