Comparative study of bottleneck-based release models and load-based ones in a hybrid MTO-MTS flow shop: an assessment by simulation

Either make-to-order (MTO) or make-to-stock (MTS) alone cannot satisfy the customer demand. Therefore, companies in different sectors are trying to adopt a hybrid MTO-MTS production strategy. Unlike MTO or MTS, there are few research on hybrid MTO-MTS environment and very few considering the operational issues. The workload control seems to handle better the operational issues in the hybrid environment considering job shop configuration whereas drum buffer rope has been designed to handle the bottleneck issue in a pure flow shop. Therefore, the objective of this paper has been defined to compare bottleneck-based release models and load-based ones in a hybrid MTO-MTS flow shop. Simulation results are not clearly in favour of one over the other, since besides severity, there is another important factor to consider: the choice of control at the dispatching level, and its connected trade-offs. In particular, implementing this control with the bottleneck-based rule is effective for MTO performances, especially in cases of high severity. Instead, when control at dispatching is absent, the workload control as a release rule is preferred, leading also to the best lead times for low severity. The results demonstrate important managerial and research implications for bottleneck-based and load-based release models in MTO-MTS flow shops.