Balanced Machine Workload Dispatching Scheme for Wafer Fab

A fab-wide dispatching scheme called balanced machine workload (BMW) which considers K-machine look ahead and J-machine look back is proposed. This research is motivated by the minimum inventory variability scheduling (MIVS) policy which considers the inventories at the next K-steps and the previous J-steps. Instead of looking at the fab flow from the step viewpoint, the BMW dispatching scheme looks at it from the machine viewpoint. The proposed dispatching scheme checks the workload of K-downstream machines and J-upstream machines for multiple products where K and J are dynamically calculated based on the current line status. Simulation results demonstrate the superior performance of the BMW dispatching scheme over MIVS.