MES, Start Production on Completed Operation

When invoking “Start Production Activity” in MES on an operation that is complete, a message box appears advising that the “Operation is already complete.”, however it does not stop the employee from beginning production activity on the completed operation. When the employee invokes “End Activity”, there is no indication of the quantity completed on the “End Labor Activity” form, so the employee enter 1 (the required quantity), clicks OK, and increments the “Completed: (quantity)” to a quantity greater than the “Run: (quantity)”.
A) How do I correct the "Completed: (quantity)?
B) How do I prevent the employee from starting activity on a completed operation in the first place?
C) How can I reopen (uncomplete) an operation on a job in the event that the operation was not really complete in the first place?

A&C: The “Time and Expense Entry” module or the “Job Adjustment” module can be used to edit labor/job quantities and change whether the op is completed or not.

B: A BPM can be created that does this. You could do an In-Transaction Pre-Processing method directive on Labor.Update or an in-transaction data directive on the LaborDtl table