1 Master Production Scheduling and A Comparison of Material Requirements Planning and Cover-Time Planning

For a company’s long-term profitability, most important processes are the way it starts parts of the manufacturing process before the customer order arrives and the way it determines and promises delivery quantities and times for the customer orders. In practical computer applications Material Requirement Planning and/or Reorder point systems are the base techniques mostly used. This article presents Cover-Time Planning, a variant of a reorder point system. Cover-Time Planning (CTP) is developed with a forward-looking forecasted demand rate and the decision variable is “time”, instead of “quantity ” for an ordinary reorder-point system. MRP and CTP are introduced and compared through a numerical ex¬ample. MRP and CTP must treat practical “make-to-order”; therefore, this paper discuss available-to-prom¬ise, planning bills, and other help systems for practical applications of Master Production Scheduling. The paper presents how and why, in practice, a Master Production Scheduling system with an available-to-promise function should be used and how this system should be designed. It is also here argued that a fully Enterprise Resource Planning (ERP) system cannot only be created by MRP, but also by CTP. Keywords