MRP is a process that uses a bill of materials (BOM) to determine when and how much of each component is needed to manufacture a finished product based on demand. For example, to make 16 units of product A requires 16 units of component D, while 2 units of D are needed for each of products B and F. MRP also uses information from master production scheduling (MSP), which provides the demand for the finished product, in this case 50 units, to calculate the component requirements.