Net Requirements Calculation 

The net requirements calculation is carried out in MRP in the planning run after the planning file check and at plant level. The system checks whether it is possible to cover requirements with the plant stock and fixed receipts already planned. In the case of a shortage the system creates a procurement proposal.

Process Flow

  1. The system calculates plant stock. For all storage locations which belong to this plant and which are not excluded from materials planning or are planned separately, the following stocks are grouped together to form plant stock:

In Customizing for MRP in the IMG activity Availability of Stock in Transfer/Blocked Stock/ Restricted Stock, you can also determine whether stock in transfer, blocked stock and restricted-use stock are included in the plant.
  1. The system also takes into account all the goods issues and receipts for a material. Receipts are, for example, planned orders or purchase requisitions and issues are, for example, customer requirements, planned independent requirements, or reservations.
  2. Therefore, the system checks to make sure that for each issue date, the requirement is covered by one or several receipts or by warehouse stock. If this is not the case, the system then calculates the shortage quantity and creates a procurement proposal. The lot-sizing procedure, scrap and rounding determine the quantity in the procurement proposal (see Calculating Procurement Quantity).

The net requirements calculation supports the following types of planning: Reorder point planning, forecast-based planning, material requirements planning (MRP). In each procedure, the system calculates the available stock differently.