Makespan and workstation utilization minimization in a flowshop with operations flexibility

Production environments where there are more tasks than workstations and any task can be assigned to any workstation are examples of operations flexibility. This paper investigates the benefits of operations flexibility in a flowshop when the goals are to minimize the makespan and workstation utilization. Furthermore, machine dominance principles are extended to the case of a flowshop with operations flexibility. The proposed heuristic framework comprises of two phases, allocation of operations to workstations and generation of job sequencing. In addition, an improvement procedure based on simulated annealing is implemented for this problem. The experimental results identify the effects of the experimental factors; show the significance of the heuristic factor; and demonstrate the tradeoff between the two performance criteria.