Creation of Purchase Orders and Purchase
Requisitions from SAP APO
Purchase orders and purchase requisitions can be created in SAP APO or in the ERP system. The following describes how SAP APO creates purchase orders and purchase requisitions, and how it determines certain purchase order data. The purchase orders and purchase requisitions are transferred automatically to the ERP system. The ERP system automatically determines certain purchase order data.
An active integration model is available for purchase orders and purchase order requisitions.
Purchase requisitions or purchase orders can be generated automatically in SAP APO using the following modules:
· SNP heuristic
The SNP heuristic usually creates purchase requisitions.
· SNP optimizer
The SNP optimizer usually creates purchase requisitions.
· Capable-To-Match (CTM)
CTM usually creates purchase requisitions.
· Deployment
You can configure whether deployment creates purchase requisitions or purchase orders.
· Transport Load Builder (TLB)
The TLB creates purchase orders only. For more information, see SAP note 381467.
· Production Planning and Detailed Scheduling (PP/DS)
PP/DS usually creates purchase requisitions. A conversion function is available in PP/DS. You can configure whether only purchase orders are transferred.

Purchase requisitions from SAP APO are fixed for material requirements planning in the ERP system and are displayed as a fixed element (*) in the stock/requirements list (transaction MD04).

When purchase requisitions are transferred from SAP APO to the ERP system, the material short text in the ERP system must be maintained in the language of the RFC connection (RFC user) between SAP APO and the ERP system. Otherwise, errors occur in the queue.
The ERP system determines the item category in accordance with the procurement form from the product-specific transportation lane in SAP APO. If no source of supply exists in SAP APO, the system determines the item category using the special procurement key maintained in the material master record.
· Stock transport order
You define the default document type of the stock transport order for the issuing and receiving plant in Customizing for purchasing. Choose Purchasing → Purchase Order → Set Up Stock Transport Order.
· Standard purchase order
You define the default document type of the standard purchase order for transaction ME21 (Create Purchase Order) in Customizing for purchasing. Choose Purchasing → Define Default Values for Document Type.
· Purchase requisition
You define the default document type for transaction ME51 (Create Purchase Requisition) in Customizing for Purchasing. Choose Purchasing → Define Default Values for Document Type.
To influence the document type of a purchase requisition or purchase order when it is created in the ERP system, you can use the customer exit EXIT_SAPLMEPI_007 within the enhancement CIFPUR02. For more information, see the Implementation Guide (IMG) for the ERP system under Integration with Other SAP Components → Advanced Planning and Optimization → Application-Specific Settings and Enhancements → Settings and Enhancements for External Procurement → Inbound Processing of Purchasing Data → Change and Enhance Purchase Order Data.
· Purchase requisition, purchase order, stock transport requisition, stock transport order
If a source of supply (product-specific transportation lane) is assigned in SAP APO, the ERP system copies the purchasing organization from the source of supply.
Otherwise, the ERP system checks whether a purchasing organization is assigned uniquely to the plant, and copies it. If the assignment is not unique, the standard purchasing organization assigned to the plant is adopted for stock transfers and for pipeline material. You define the assignment in Customizing under Enterprise Structure → Assignment → Materials Management → Assign Purchasing Organization to Plant.
In SAP APO, you can maintain minimum and maximum lot-sizes that differ from the product master, as well as the rounding value and the rounding profile. This occurs in the transportation lane and within the product-specific means of transport using a lot-size profile.
· Purchase requisition
The quantity is adopted from SAP APO. The ERP system no longer rounds.
· Purchase order
The quantity is adopted from SAP APO.
Note that in SAP APO the rounding occurs in relation to the base unit of measure. This means that it is possible to convert consistently to the order unit in the ERP system. This means that the rounding rules in SAP APO must correspond to those in the ERP system. Example: If the base unit of measure is piece, and the order unit is defined as packet, with 10 pieces = 1 packet, a purchase order for 75 pieces results in an order unit of 7.5 packets.