Optimal partitions for shop floor control in semiconductor wafer fabrication

Wafer fabrication is a very complex manufacturing process. It is imperative that the mean and the variance of the cycle time be kept small. For the purpose of scheduling, the set of wafer fabrication process steps need to be partitioned into zones of roughly equal sizes, where size refers to the sum of the processing times of the steps in a zone. By formulating the problem as a dynamic program, the paper finds the optimal partition so that the sum of the sequares of the deviations from a target size is minimized.