Abstract: Allocating limited manufacturing resources to achieve a feasible production plan that is consistent with customer demand is a difficult and common problem faced in many manufacturing industries. For large-scale multi-stage manufacturing systems, existing methods are typically based either on allocating limited resources sequentially, according to a priority ranked list of production starts, or on linear programming based models. The output of such planning models is a production plan which specifies the quantity of each part to produce at each plant, using resources available to the enterprise. Typically there are lot-sizing rules defining the permissible production start quantities. The invention disclosed herein is a method for applying these rules to the lot-sizing of production starts within a linear program. It employs advanced heuristics that consider both established operational objectives (e.g.

Abstract: Disclosed is a method and system for efficiently modeling the situation where a product manufactured within a multi-stage manufacturing system has components upstream in the supply chain which may substitute for one another. The invention selectively permits substitutions based on rules associated with downstream operations or customer shipments. One component may substitute for another provided that the assembly consuming the component belongs to a certain set of assemblies. The invention also encompasses a method by which this can be integrated into a production planning system based on a linear programming (LP) model.