We use the above structure [or physical tables] with appropriate bBusinessObject.nBusinessObjectRole values to construct even more Purchase Entities.

So, if we use the  Purchase Shipment Entity with a nBusinessObjectRole= 4503 we create the Return of a PurchaseShipment !!

and if we use the Purchase Payment Entity with a nBusinessObjectRole= 4102 we create the Return of a Purchase Payment !!


You can find a complete list of nBusinessObjectRole values in the project area of the business applications.


*Note that, depending on the nBusinessObjectRole value, BPs are called to insert, update, delete or post Purchase Entities and there is nothing special in the nBusinessObjectRole(s) values.