In a profitable service department, the labor has to be 25% (or less) of sales and material 10% (or less).
If you are not at these numbers, I need to look at your flat rate pricing, your parts multipliers and your service tickets!
Notice in both cases, win or lose, the tech makes the "lions share" of the money.
Remember, if you want to increase your sales and profits, "Go up on your prices".