When I managed CiCis units in Arlington TX 10 years ago, food cost was calculated using the standard formula of last weeks ending inventory, plus this weeks receipts, minus this weeks ending inventory. It actually wasn’t too bad, as they keep their number of inventory skus very low. If I remember correctly, goal was about 17% food cost. I did hear of some stores weighing waste, but that was in stores with high food cost, usually to prove they weren’t rotating their buffet correctly. i.e., if you suspected your assistant manager wasn’t managing the buffet efficiently in your absence, you could compare the waste level on his shift with a similar shift of yours. The CiCis system that refined, its a thing-o-beauty! (if you don’t like good pizza, that is…)