Everyone needs to use the system that works best for them. I was taught to do yield specs and to apply the waste of prep back into the cost thus elevating the price per unit to an actual price per usable unit. Come on John Maxwell, your technique makes sense. While food cost is a valuable gauge to a kitchen's efficiency I have long been an advocate that gross profit is a far more important figure. Restaurants rent tables and chairs for specified periods of time.
Customers select offerings that suit their liking and that they perceive as good values.
I'd be very interested in what you all think about this. That indicator has to be an easy to understand measure of performance. Food cost has long been the most widely used indicator and it is fairly accurate. It has been easy to use and easy to understand. But its profit that drives every business.