In this business scenario Company A accept the sales order of customer and asked third company/Vendor to deliver the goods and bills you. Subsequently you raise the invoice to the customer.
In this scenario Material type plays important role. While creating material in material master, material type to be selected as Trading goods and Item category group is BANS in sales :Sales org 2 tab and Procurement type to marked as F in MRP 2 Tab.
The Billing relevance in item category should be F - Order-related billing doc. - status according to invoice qty.
This is standard schedule line category is provided by SAP for Third party Sales.
CS triggers purchase requisition automatically in the back ground when save the sales order.
Note: If you need to created your own config based on business requirement w/o disturbing standard configuration, then copy it and make necessary changes. But, kept key factors in view.
CS to TAS in TCode VOV5 and TAS to your order type in TCode VOV4.
1. Company ABC creates Sales order and Saves it. As soon as it is saved Purchase requisition is created in the back ground (Due to schedule line category).
2. The authorized person @ Company ABC converts that PR to purchase order and ask vendor to supply the goods to the customer.
3. The vendor sends the invoice for the delivered goods to the company ABC. Company ABC verifies the Invoice and do a invoice receipt for the invoice recieved form Vendor
4. Finally Company ABC raise invoice to the Customer.
It is assumed that MM and SD module configuartions are in place.