Employee Efficiency Reporting

I am wondering if anyone else out ther has this business scenario...

We have Operators and Assistants working on an Operation.
However, only the Operators report Qty; thus only Operators acheive
Earned Hrs. Additionally, when an Operator is moved to be an Assistant
on another machine because their machine is not running (planned and
unplanned) we want to exclude those hours as we don't want to penalize
the Operator for not achieveing Earned Hrs for those Labor Detail

Our challenge is now running Emloyee Efficiency. We have had to come
up with alternative reporting/calculations which has been extremely

Any thoughts or suggestions would be apprecieted.
Patty Buechler