Why Backflush of Items is choosing different Lots from the Lots that is Pick Confirmed and Reserved

Summary:

Hi All,

During UAT we found an issue and observed that, Work Order Component Item Lot Numbers assigned at Pick Confirmation are changing during the Material Backflush on Work Order.

Backflush of Items is choosing different Lots from the Lots that is Pick Confirmed and Reserved. After picking and pick-confirming lot numbers, when work order is executed and raw material is backflushed, we see that some items have different lot numbers picked for backflush compared to pick release based lots.

There is a rule of FEFO on both picking rules and backflush lot pick rules. They are both Lot FEFO and this problem did not occur before during SIT.