1. A method for computing a production plan for part numbers (PNs) throughout a bill of material supply chain, comprising the steps of: separating a bill of materials (BOM) into separate manufacturing stages; partitioning each manufacturing stage of the separate manufacturing stages into a heuristic processing and a linear programming processing partition; assigning PNs to the partitioned manufacturing stages; calculating for the each manufacturing stage a Material Requirements Planning (MRP) production plan using either the heuristic processing or the linear programming processing depending on the partitioning step; calculating for the each manufacturing stage a best-can-do production plan using one of the heuristic processing and the linear programming processing depending on the partitioning step; and preparing MRP production solution information to be passed recursively at least one of forward and backward to a manufacturing stage of the separate manufacturing stages based on the best-can-do calculating step.