Minimizing total weighted tardiness on a batch-processing machine with incompatible job families and job ready times

Semiconductor wafer fabrication facilities (‘wafer fabs’) strive to maximize on-time delivery performance for customer orders. Effectively scheduling jobs on critical or bottleneck equipment in the wafer fab can promote on-time deliveries. One type of critical fab equipment is a diffusion oven which processes multiple wafer lots (jobs) simultaneously in batches. We present a new polynomial time Batch Improvement Algorithm for scheduling a batch-processing machine to maximize on-time delivery performance (minimize total weighted tardiness) when job arrivals are dynamic.