ATP Reschedule is not considering the delivery date change of MRP element ShpgNt

[former_member116200]

Issue Background:

We have 100 pieces of material A available in storage location 0001, and an inbound delivery with 200 pieces planned to be received on 2018.11.07. With this availability situation, a sales order was placed requested to be delivered on 2018.11.09 with 300 pieces. Since the receipts could be satisfied with the requirement, the schedule line was confirmed as requested and the confirmation status is "All items confirmed":

With this background, now the goods receiving delay is happening on the relevant purchase order, it is delayed to 2018.11.14. This acutally causes the over confirmation for the original sales order, and ATP reschedule is required.

I'm now going to run V_V2 to have this material rescheduled by using the variant below, but the system replies "There are no entries in the backorder list".

I realize that this is because the confirmation status of the sales order is acutally confirmed while I check the "Unconfirmed documents required" in the variant. Normally, we used to check this option to prevent all transactions already confirmed into the reschedule scope. If deselecting the indicator, the quantity of data to be processed will highly increase.

Does any SD expert has any idea for this kind over confirmation? what is the best solution to have ATP updated in case of the purchase order delay?