Minimizing Makespan and Workstation Utilization in a Flowshop with Operations Flexibility

Operations flexibility refers to production environments where there are more tasks than workstations and any task can be assigned to any workstation. This article investigates the advantages of operations flexibility in a flowshop when the objectives are to minimize the makespan and workstation utilization. The proposed heuristic framework consists of two phases, allocation of operations to workstations and generation of job sequencing. Moreover, an improvement procedure based on simulated annealing is implemented for this problem. Experiments are conducted to: analyze the impact of operations flexibility; demonstrate that schedules that are makespan optimal may not be machine utilization optimal and vice versa; and analyze the performance of the proposed heuristics.