PURPOSE: To reduce the stock of parts/half-finished goods, and to improve flexibility against the change of order received by optimizing an expectant production plan by setting a coefficient on a parts list for planning, and allotting the expectant production plan for the order received in the manufacturing industry to produce the goods on the expectant order received basis.

CONSTITUTION: A planning parts list information storage part 1 and a planning parts list information updating part 2 to update it are provided. Planning parts list information is intrinsic information related to an item and constitution necessary for developing expectant manufacturing order. Further, an expectant production plan information storage part 3 and an expectant production plan information updating part 4 to update it are provided. An expectant manufacturing order developing part 5 refers to the information of the storage parts 3, 5, and develops the manufacturing order, and stores it in an allotment information storage part 6. On the reception of the order, an order received allotment processing part 7 refers to expectant manufacturing order information and order received information from the storage part 6, and allots the order received. A short allotted parts list output part 8 refers to the storage part 6, and outputs a short allotted parts list.