User exit for return from delivery - 651 movemment type in WM

Question

Hi Guru,
We are going to implement a customize program to control the putaway storage location when the HU returning from delivery in WM environment.
The process is as below:
1. Create the return order with reference to the original billing document;
2. Create the return delivery (original storage location is 0001).
3. Manually attached the HU we want to return to the delivery ;
<<<< 4.LT03 to create the TO for this delivery. >>>>>
         - then it will automatically PGR (material document with 651 movement type) 
         - A TO will automatically created and from 904 to another destination storage type 101 (setup in the 651 movement type).
The requirement is: we need to change the storage location when the TO (904 to 101) is confirmed according to some logic.
We found that we can not use the user exit "EXIT_SAPLL03T_001 - User Exit at End of TO Creation (in Update Task)" or   'EXIT_SAPLL03T_002 - User Exit at End of TO Confirmation (in Update Task)". We set the break point, but it didn't stop there.
Any one can help us where we can put our code in?
Thank you very much,

Answer 1

Hello!
The user exit MWMTO001 (FM EXIT_SAPLL03T_001) runs usually in Update
Task. That means that you have to switch on the update debugging in
order to let the debugger stop in this exit. In most cases update
debugging isn´t switch on when the debugger doesn´t stop in the exit.