Unfortunately, most systems available either cause dispensing problems or can easily be overcome by staff. The best method that I am aware of is to physically measure inventory on a regular basis. There are companies that will inventory not just the draught but all bar inventory and report removals to the gram. Most certainly, if the receipts do not match the removals, there probably needs to be a significant intervention as to staff training and policy.
Scott Zuhse, Instructor
Micro Matic Dispense Institute