To provide a system capable of easily and surely determining the number of units to be produced by preventing the occurrence of misses and troubles due to miscalculation or information leakage in a process to be executed with much time in each reception of order in a conventional number-of- products determination system for stock production.

The system prepares a preparing work data base (preparing WK DB) extracting products required to be newly produced based on information such as order information, stock information and production mechanism and determines the number of units to be produced individually in each product stored in the data base. Various data such as lacking information after allowing an order, future order expectation information and stock information which are necessary for determining the number of units to be produced for the product concerned are displayed on the screen of a display device so that information for determining the number of units to be produced can be simultaneously obtained. Thus the number of units to be produced can easily be determined by referring to the product information of each product.