An order acknowledgment received by EDI results in a purchase order being generated in the receiving system. A customer can use this function, for example, to obtain information on sales orders that the vendor generated by planning replenishments for the customer. A purchase order is generated in the R/3 system of the customer, the "opposite" of the sales order generated by the vendor.

The number of the sales order is entered in the purchase order as a reference. The system then sends a change message to the vendor indicating the purchase order number generated in the customer system.

• Vendor field

• Customer (sold-to party) field

You assign a purchasing organization and purchasing group to a particular combination of vendor and sold-to party in the details data. The purchasing organization and purchasing group must be known when you create a purchase order. These do not, however, appear in the IDoc. This is why the system determines them from the organizational assignment data when the IDoc is received.

The vendor can also send an external goods recipient number under which a site in your company is managed at the vendor's. For the system to be able to convert this number when an IDoc is received to an internal site number, you enter the external number in the Customer (goods recipient) field and the internal number of the site to receive the goods in the details data.

You can also specify the purchasing document to be used when a purchase order is created for the vendor. If you do not enter any purchasing document type, the system uses that defined in Customizing for the creation of a purchase order online.

• You must select the indicator allowing the vendor to enter purchase orders in the Purchasing data of the vendor master record of the vendor sending the order acknowledgment .
• An RP type must be entered in the site data for the article. This RP type must be assigned a "planning by an external system" planning method.
• You must create purchasing information records for the articles and vendor concerned. You can also enter the vendor article number in the purchasing information records, thus allowing your system to identify and convert the number if the vendor IDoc only contains the vendor article number.

This function processes IDocs of the message category ORDRSP and message variant VMI. Before purchase orders are generated, the system calls the user exit EXIT_SAPLWVMI_003 via which you can change the data of the inbound IDoc.

This enables you to convert vendor article numbers to the article numbers you use as you require. If a purchase order cannot be generated, because the data is incomplete, for example, the system triggers a workflow.

For the system to transfer the purchase order number to the vendor system after the purchase order has been generated, an IDoc of the message category ORDCHG is used with the message variant VMI. The system only sends this message if you maintained a partner profile for this message category.