Scheduling manufacturing systems with work-in-process inventory control: single-part-type systems

Abstract

A real-time algorithm is developed for scheduling single-part-type production lines with work-in-process inventory buffers. We consider three classes of activities: operations, failures and repairs, and starvation and blockage. The scheduling objectives are to keep the actual production close to the demand, the work-in-process (WIP) inventory level low, and the cycle time short. A three-level hierardhical controller is constructed to regulate the production. At the top level, we determine the desirable buffer sizes and the target production level for each operation. At the middle level is a production flow rate controller that recalculates the production rates whenever a machine fails or is starved or blocked. The loading times for individual parts are determined at the bottom level of the hierarchy. The production scheduling algorithm is evaluated by using computer simulations for a variety of cases. Compared with a transfer line policy, a significant improvement in system performance is observed.

Additional information

Notes on contributors

S.X. BAI

Sherman X. Bai received his Ph. D. in Operations Research from the Sloan School of Management of MIT, in September 1991. Since September 1991, he has joined the faculty of Industrial and Systems Engineering Department at the University of Florida, Gainesville. His research interests are in the areas of Manufacturing Systems Modeling and Analysis, Digital Simulation, Optimal Control, and Dynamic Game Theory.

S.B. GERSHWIN

Stanley B. Gershwin received the B. S. degree in Engineering Mathematics from Columbia University in 1966, and the M. A. and Ph.D. degrees in Applied Mathematics from Harvard University in 1967 and 1971 respectively. In 1970-1971, he was employed by the Bell Labs and from 1971 to 1975 he worked for the Drape Laboratory for Information and Decision Sciences of MIT. In 1986-1987, he was a Professor in the Manufacturing Engineering Department of Boston University. He is currently a Senior Research Scientist in the Department of Mechanical Engineering of MIT, and is affiliated with the Laboratory for manufacturing and Productivity. His major research interest is on systems issues in manufacturing.