A modified shifting bottleneck heuristic for minimizing total weighted tardiness in complex job shops

Abstract

Increases in the demand for integrated circuits have highlighted the importance of meeting customer quality and on-time delivery expectations in the semiconductor industry. A modified shifting bottleneck heuristic is developed for minimizing the total weighted tardiness in a semiconductor wafer fabrication facility. This ‘complex’ job shop is characterized by re-entrant or re-circulating product flow through a number of different tool groups (one or more machines operating in parallel). These tool groups typically contain batching machines, as well as machines that are subject to sequence-dependent setups. The disjunctive graph of the complex job shop is presented, along with a description of the proposed heuristic. Preliminary results indicate the heuristic's potential for promoting on-time deliveries by semiconductor manufacturers for their customers' orders. Copyright © 2002 John Wiley & Sons, Ltd.