Any service managers or ex service mangers?

I wouldn’t implement some that’s going to be a ton of work to administer and cause division. Institute a program based on a half dozen shop goals such as sales, profitability, safety, warranty claims,etc.Pay no more frequently than quarterly (progress pay out) perform quarterly employee reviews and factor the bonus based on earned wage and performance factor ie 0.7 if you’re below par and 1.25 if you’re the best. There should be no surprises. Make sure and weed out non performers (not those still learning) which you should be doing anyway.