Production scheduling algorithms for a semiconductor test facility

The operations in the facility under study are characterized by a broad product mix, variable lot sizes and yields, long and variable setup times, and limited test equipment capacity. The assignment of products to testers varies depending on device and package type as well as temperature. The proposed approach starts with the division of the facility or job shop into a number of workcenters. The workcenters are then sequenced one workcenter at a time. A disjunctive graph representation of the entire facility is used to capture interactions between workcenters. The introduction of different management objectives leads to different workcenter problems and different production scheduling algorithms. Algorithms for two different workcenter problems are presented. Directions for future research are also discussed