Applying constraint management theory in a wafer fab

This paper reviews National Semiconductor´s experience in applying constraint management techniques at an integrated circuit wafer fabrication factory in South Portland, Maine. It explains why constraint management was undertaken and the effect that constraint management techniques have had on product shipments, inventory, cycle times, and due date delivery performance. The process of identifying bottleneck tools, the methods used to increase tool output, and the synchronization of tool output and inventory are described. The effect of factory indices and information systems on employee behavior and the strategies used to convince people to behave differently are also described. The theory of constraint concepts is briefly reviewed