Push and Time at Operation strategies for cycle time minimization in global fab scheduling for semiconductor manufacturing

Abstract : This paper investigates two global scheduling strategies for cycle time minimization in semiconductor manufacturing. These global scheduling strategies represented as a linear programming models are compared to a First-in-First out dispatching rule. The first global scheduling strategy is a Push strategy, in which products are pushed to their final operations using high Work-In-Process holding costs on the first operations. The second global scheduling strategy is a Time at Operation strategy, where Work-In-Process quantities that have arrived at different times in an operation are penalized differently. The computational results performed on industrial data using the Anylogic simulation software coupled with IBM ILOG CPLEX show that the Time at Operation strategy minimizes the cycle time while maintaining a high throughput compared to the Push strategy and the simple First-In-FirstOut dispatching rule. The paper also shows, when production targets are determined using the Push strategy, products with a large number of operations are prioritized.