Production plan creation method, production plan creation program, and production plan creation device

摘要

PROBLEM TO BE SOLVED: To determine the optimum production configuration within a range of facility capacity even when fluctuation of facility loads and fluctuation of demands occur.SOLUTION: Pieces of basic information regarding periods, passed process routes, raw material costs/selling prices, a range of production (a production upper limit value and production lower limit value), facility capability (facility utilization capability and overtime capability), overtime costs, evaluation indexes (a value obtained by subtracting the overtime costs from marginal profit ratio) are read (STEP 1). The marginal profit ratio and facility load basic units for every period are calculated for every passed process route (STEP 2, 3). The production of the respective periods of the respective passed process routes where an evaluation index becomes the maximum is calculated by linear programming while satisfying facility capability restriction that the total loads for every period of the respective facilities calculated from the facility load basic units do not exceed a value obtained by adding the facility utilization capability to the overtime capability, and upper and lower limit range restriction of the production that the total of the production for every period of the respective products is within a range equal to or more than the production lower limit value and less than the production upper limit value is satisfied, and calculation results are output (STEP 4, 5).