An Assessment of Order Release Models in Hybrid MTO-MTS Flow Shop with Bottleneck

The traditional configurations of market response, make-to-order (MTO) and make-to-stock (MTS), are no more suitable in today’s competitive context, forcing companies to a transition towards hybrid solutions. Unfortunately, this has been neglected, in particular at the operational level where the Order Review and Release issue counts only two related articles but restricted to job shops. Therefore, researchers are moving towards flow shop configuration, particularly addressing the issue of bottleneck. Literature links this topic to the Theory of Constraints by Goldratt and Cox [14], from which Drum Buffer Rope (DBR) has been designed as a production planning and control tool. The objective of this paper has been defined as verifying how the decision on the release model changes considering the designed hybrid flow shop model. Simulation results are not clearly in favor of one over the other, since besides severity, there is another important factor to consider: the choice of control at dispatching level, and its connected trade-offs. In particular, implementing this control with bottleneck-based rule is effective for MTO performances, especially in case of high severity. Instead, when control at dispatching is absent, the workload control as release rule is preferred, leading also to the best lead times for low severity.