MRP areas

By default MRP plans a material for a whole plant: all storage locations together. Sometimes that is wrong. Components on the assembly line should be replenished separately from the main warehouse, or stock at a subcontractor should not be counted as available in Detroit. MRP areas let you plan parts of a plant separately, with their own planning parameters and their own stock/requirements list.

What changed in SAP S/4HANA

• Planning at storage location level (excluding a storage location or planning it separately in the material's storage location data) is not available. Storage location MRP areas replace it.
• MRP areas no longer need to be activated in Customizing; you create them directly (transaction OMIZ in the IMG path for MRP areas).
• For subcontracting, SAP recommends subcontractor MRP areas. They do not have to be assigned to every material: if a component has no MRP area segment, MRP plans the area with default parameters.
• Each MRP area has its own planning file entry, so it can be planned independently.

A storage location MRP area at Contoso

Contoso keeps line-side components for the alternator line in storage location 171L, close to ASSY-10. The design creates a storage location MRP area for 171L. Fastener kits are planned there with replenish to maximum stock: when stock falls below the reorder level, MRP proposes a stock transfer from the plant MRP area. The plant MRP area plans the purchase from the supplier. The line never runs out, and the warehouse sees transfers it can plan.

Subcontractor MRP areas

SAPinsider's walkthrough of the S/4HANA approach describes a subcontractor MRP area as MRP area type 03 (supplier), tied to a plant and representing one subcontractor. Components provided to the subcontractor are planned in that area, so stock at the subcontractor is not counted as available in the plant. In the stock/requirements list you can display the MRP area to see the subcontractor's situation; at plant level, stock transfer requirements show what must be sent. As a what-if, if Contoso outsourced stator winding, the stator cores at the winder would sit in a subcontractor MRP area.

MRP areas are planned like small plants. Each one can have its own MRP type, lot size, MRP controller and safety stock in the product's MRP area segment, and each shows up as its own stock/requirements list. That is powerful and easy to overuse: every extra area is another list a planner must watch and another set of master data to maintain and test. Create an area when the business genuinely plans that stock separately, not because a storage location exists.