Serial numbers in Goods issue

Question

Hi All,
We have an existing Warehouse management process where the Goods issue is first posted. This creates a transfer order. The IDOC created by the transfer order tells the external system to Pick a material.
Now we are trying to introduce serial numbers to certain materials. The problem we are facing is that, it is not until the material gets picked up at the warehouse that we know what the serial number is. 
So, is there a way to create a Goods issue first, then once the material gets picked up, update the goods issue ( or the serial number history ) with the serial number that actually gets picked up.
Thankyou for your suggestions! 
- Sekhar

Answer 1

I am thinking you can update the serial numbers even after goods issue, try VL02N and check if the system allows.  If it does allow use the following FM to update the serial numbers:
Ensure you sort the serials by position otherwise the update might not work.
fails to update properly
    SORT lt_serials BY rfpos.
  Update delivery table with serials
    CALL FUNCTION 'WS_DELIVERY_UPDATE'
      EXPORTING
        vbkok_wa              = lwa_vbkok
        delivery              = i_vbeln
        commit                = 'X'
        it_sernr_update       = lt_serials
      IMPORTING
        ef_error_sernr_update = l_sernr_update
      EXCEPTIONS
        OTHERS                = 99.
hith
Sunil Achyut