Hi,
I am not sure why you allow user to post document with transaction code MB1B for movement type 311 and again you want to monitor the same?
Better follow 2nd option provided in my above reply and restrict of using 311 movement type for transaction code MB1B, so that all your users will use transaction code:ZSLTRANSFER with movement type 311 for stock transfer between storage locations.
Regards,
Biju K