No-wait two-stage multiprocessor flow shop scheduling with unit setup

A well-arranged production schedule enhances equipment utility rate by distributing limited resources properly, which also improves efficiency and reduces costs. No-wait operations are among the most common production models. A wet batch in semiconductor packaging processes, for instance, is restricted by technical factors such as the chemical dye, which cannot be exposed to air for prolonged periods. Thus, a no-wait process between batches is necessary. This study considers a no-wait two-stage multiprocessor flow shop with setup time that minimizes total completion time. Integer programming model and an ant colony optimization (ACO) heuristic were implemented to test, analyze, and compare simulated data. The ACO results revealed that efficiency was substantially better than that achieved by integer programming, and the heuristic solutions were quite satisfactory.