A hybrid two-stage flowshop with part family, batch production, major and minor set-ups

In this paper, we consider a two-stage hybrid flowshop with a single machine at stage 1 and multiple identical machines at stage 2. The flowshop is characterized by major and minor setups, part families and batch production allowing split and no split at stage 2. The parts within a family share a major setup and the parts in a batch share a minor setup. The objective of our problem is to minimize the makespan. We develop two allocation policies with one as a traditional way (called Forward Heuristic) and the other as a non-traditional way (called Backward Heuristic). We also develop several effective sequence rules to further improve the makespan. The computational results show that the Backward Heuristic, in general, is superior to the Forward Heuristic. The sequence rules developed in this paper also perform better than the traditional sequence rules such as SPT and LPT.