Abstract: A method for using a computer to control the manufacture of items in a factory determines when to schedule the manufacture of a new batch of an item or the ordering of a new batch from an outside supplier by comparing an item's reaction capacity with a limit above which the reaction capacity should lie. The limits are computed, on the basis of sales forecasts and bill of materials information, to be limits adequate to meet the forecast need for commercial items produced by the factory. The reaction capacity is recomputed and compared with the limit at a plurality of control dates. In computing an item's reaction capacity, the physical inventory, the pending orders for additional supplies of the item, the unfulfilled customer demand for the item, and the demand for the item from within the factory are all taken into account.