Class A: Closed-loop system used for both priority planning and capacity planning. MPS is levelled and useed by top management to run business. Most deliveries are on time inventory is under good control, and there is little or no expediting.

Class B: Closed-loop system with capability for both priority planning and capacity planning. However, MPS is somewhat inflated. Top management does not give full support. Some inventory reductions have been gained, but capacity is sometimes exceeded and some expediting is neccessary.

Class C: Order launching system with priority planning only. Capacity planning is done informally with an inflated MPS. Expediting is used to control the flow of work. A slight reduction in inventory has been acheived.

Class D: The MRP system exists mainly in data processing. Many records are inaccurate. The informal systems effectively run the company. Littel benefit is obtained from the MRP system.