Scheduling for parallel machines with family setup times

This paper considers identical parallel machine scheduling problem. Each job has a processing time, due date, weight and family type. If a different type of job is followed by prior job, a family setup is incurred. A two phased heuristic is presented for minimizing the sum of weighted tardiness. In the first phase, using rolling horizon technique, we group each job into same family and schedule each family. In the second phase, we assign each job to machines using schedule obtained in the first phase. Extensive computational experiments and comparisons among other algorithms are carried out to show the efficiency of the proposed algorithm.