Effect of express lots on production dispatching rule scheduling and cost in final test process of LSI manufacturing system

In order to evaluate the effect of express lots on production dispatching rule scheduling and cost, we applied the event-driven simulation analysis to a real final test facility of one-chip microcomputer. Simulated results show that when the dispatching rule in the express lot assignment is changed from usually used FIFO rule to JIG+RPM rule, the allowable percentage of express lots in total arrival lots increases from 15% to 55%. In JIG+RPM rule, the time required for jig exchange and for temperature change, and also the remaining processing time of the machine in use are considered.