Rescheduling strategies for minimizing total weighted tardiness in complex job shops

Production scheduling is a complex task in most real manufacturing settings and semiconductor manufacturing is no exception. Fabricating integrated circuits on silicon wafers is arguably one of the most complex and expensive manufacturing processes in existence. As technology demands increase, the business of semiconductor manufacturing becomes more difficult. Pressing due dates and massive late penalties, coupled with increased demand, require semiconductor manufacturers to control their wafer fabrication facilities (wafer fabs) efficiently. Although scheduling techniques often provide the needed control in these complex job shops, wafer fabs are dynamic entities that often require rescheduling due to unplanned machine failures, the introduction of high priority jobs and other events. Three different strategies are examined for rescheduling complex job shops, while investigating the efficacy of each strategy to maximize on-time delivery performance (minimize total weighted tardiness).