I have referred many discussions on this but not a constructive solution.
We have a situations where the statistical delivery date in the purchase order is past than the Document data as well as the delivery date of PO- see attached. ?
one recommendation was to convert the available warning message (ME 589) to error but that could jeopardize the process of AUTO PO as it will fail all of the PO's that has PR dates in the past.
in our case mostly the stat del dte is going exactly a year back to the delivery date in the PO (no history of such item change in PO) and that is making it difficult for vendor evaluation.