Optimal Manufacturing Flow Controllers: Zero-Inventory Policies and Control Switching Sets ∗ Michael H. Veatch, † Gordon College Michael C. Caramanis, ‡ Boston University June 1998 Abstract A continuous flow control model of a single workstation with multiple failure modes and part types is considered. Although the general model is intractable, properties of the optimal control policy are identified that can be used to help formulate heuristic policies. Control switching sets are described and shown to have a threshold form. For a single machine with two part types, conditions are found under which no inventory is held, analogous to the single part type result of Bielecki and Kumar. * This research was supported by National Science Foundation grant DDM-9215368. † Department of Mathematics, Gordon College, Wenham, MA 01984, (978) 927-2300, FAX (978) 524-3747, veatch@gordonc.edu ‡ Department of Manufacturing Engineering, Boston University, Boston, MA 02215, (617) 353- 3247, FAX (617) 353-5548, mcc@buenga.bu.edu 1