A method for controlling a production apparatus includes steps of providing production information in the form of a specified production time period with respect to a plurality of product types, calculating a production expectation value for each specified production time period, summing the production expectation values for each specified production time period for all the product types and then integer-processing the total number of product portions to be produced each day, providing each day with as many production orders as the integer-processed number of product portions to be produced on that day, and then determining by an average process what product type should be produced in each production order.