P47131 Back Order quantity not correct for Quantity Increase (QI) transaction
P47131 (EDI Purchase Order Change Edit/Create),
does not take existing order quantity into account when an Order Quantity Change Increase transaction is processed.
QI (Quantity Increase) transaction is in File: F47132 Field: SZCHGC (Change Code)
As a result the Back Order quantity is not correct.
Note: I know P47131 calls P42997 (Inventory Availability/Commitment) which I believe is used to determine the item availability and changed Sales Order quantities.
Also, I tested Sales Order Quantity increase with P4211 using the same order (as used in P47131) and the Back Order Quantity is correct.
Not sure why there is a difference (in the Back Order quantity) between P47131 and P4211 when I increase the Order quantity.