Goods Movements for Purchase Orders with a Final Account Assignment Indicator 
In items with a final account assignment indicator (FAA indicator) you can only post further goods receipt quantities up to the level of the final account assignment quantity (FAA quantity) that the system determined when the FAA indicator was set.
Prerequisites
You have set the FAA indicator for at least one account assignment item (AA item) in the purchase order. For further information, see Setting the Final Account Assignment Indicator in Purchase Orders.
Features
Clearing an Invoice Surplus
If there are quantities that have been invoiced but not yet delivered, the system determines the FAA quantity based on the invoice quantity. In that case the FAA quantity is higher than the quantity of goods received posted to this assignment up to now. To clear this invoice surplus, the system distributes further partial goods receipt quantities to items with an FAA indicator up to the level of the FAA quantity. The system distributes quantities according to the following logic:
First, the system distributes the quantity of goods received proportionally across all AA items with an invoice surplus, regardless of whether these items have an FAA indicator or not.
Once the invoice surplus has been cleared, the system distributes the goods receipt surplus on a progressive fill-up basis to items with an FAA indicator, up to the level of the FAA quantity.
Finally, the system distributes the remaining quantity of goods received, in accordance with your settings in the partial invoice indicator, across all AA items without FAA indicators.
Creating Return Deliveries
In the case of return deliveries, the system distributes the quantity being returned proportionally across the account assignments of the purchase order items, so that the quantities, including those of the items with an FAA indicator, are reduced accordingly. The next time there is a partial goods receipt, the system distributes the quantity to AA items with FAA indicators up to the level of their respective FAA quantities. If you create return deliveries for purchase orders with distribution by quantity or percentage distribution, and you want to distribute the returned quantity to the account assignments manually, you can use the example implementation CL_EX_MB_ACCOUNTING_DISTRIBUTE of the BAdI: Multiple Account Assignment - Redistribution in Goods Receipt (MB_ACCOUNTING_DISTRIBUTE). The system then displays an additional screen, on which you can manually overwrite the proposed distribution, check your new distribution, or reinstate the original distribution suggestion.
Overdeliveries
If you allow overdeliveries for a purchase order item with multiple account assignments, and enter overdelivery tolerances on the Delivery tab, the FAA indicator influences the distribution of the overdelivered quantities:
You have set the FAA indicator for individual AA items before you create an overdelivery for the purchase order item.
The system calculates the allowed level of overdelivery based on the purchase order quantity, and distributes the overdelivered quantity solely to items with no FAA indicator. Subsequent overdeliveries do not increase the FAA quantity that the system has already determined for items with an FAA indicator.
You create overdeliveries before you set the FAA indicator for individual account assignment items.
Overdelivered quantities that were created for an AA item before the FAA indicator was set increase the quantity of goods received of that AA item. Since the system determines the FAA quantity based on the quantity of goods received and the invoice quantity, the FAA quantity also includes overdeliveries that are entered as goods receipts. This can have the effect that the FAA quantity of an AA item exceeds the originally ordered quantity. In the same way, in later reversals or return deliveries the system does not match the FAA quantity to the ordered quantity, and it distributes quantities from substitute deliveries to AA items with FAA indicators up to the level of the FAA quantity.