Automatic distribution of serial numbers took place - Check PO

What causes this issue?

You are carrying out an unplanned material exchange (UME) for the
subcontract purchase order item with a quantity greater than 1. You have
used serialized materials and the serial numbers have been maintained
for the original purchase order item.
You have exchanged the original material with two or more
interchangeable materials during UME and split the quantity in the UME
dialog box.
When creating the new subitems in the purchase order, the system is
trying to distribute the assigned serial numbers proportionally between
all new subitems. The automatic distribution is a proposal from the
system.

System Response

The system updates the purchase order and creates new subitems. The
system carries out automatic distribution of the serial numbers. In the
application log of the Subcontracting Monitor, the system issues a
warning message regarding the automatic distribution of the serial
numbers for each relevant subitem.

How to fix this error?

Check in the purchase order whether the automatic distribution of the
serial numbers is correct and adjust if required.
The automatic distribution of serial numbers happens only for a
recursive repair for the items you select in the UME dialog box, where
you have selected the <LS>Material Change</> check box.

Procedure for System Administrators

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

Error message extract from SAP system. Copyright SAP SE.