Integrating m-Machine Scheduling into MRP

This paper presents an approach to integrate the m-machine production scheduling into Material Requirements Planning (MRP). In general, generating MRP considers only Bill of Materials (BOM) and ignores capacity constraints and operating sequences; therefore, a production plan is unachievable when scheduling is actually performed next on shop-floor. That is why recent research has focused on executing both MRP and scheduling simultaneously. Our approach uses an integer linear programming model to plan and schedule concurrently to look right through the capacity constraints and operating sequences. The objective function of the proposed model considers both planning and scheduling purposes that is to minimize total inventory costs and order´s tardiness. All significant and inevitable concerns when separately generating MRP and schedule are incorporated with the model through several constraints. Numerical results show that this model can be used to simultaneously generate reasonable MRP as well as feasible and optimal m-machine production schedule.