Work orders - Lot number

Hi,

R12.2.9

Quick question on work orders.

We have an open work order to create multiple Finished goods.

Using Move Transactions->Complete partial quantity like 1 Finished goods at a time.

This Item is lot controlled. How to assign lot number to this FG item.

There a lot number field in work order-> mote tab.

But we need unique number whenever we complete the quantity in this work order.

Basically same WO is used to produce multiple Finished goods over time.

Is there a way to assign lot number in the move transactions-> complete.

Please advise

thansk