Logistics Planning & Control.

Value-added (廚藝的價值) = value of outputs (菲傭賣家鄉菜給同鄉的價) - cost of inputs (菲傭從僱主家偷的食材之價)

Productivity (生產力) = Outputs (蒸蛋糕的味道 + 收禮者的喜悅 + 臉書like數) / Inputs (材料錢$26 + 材料量一盒鮮奶 + 每糕花我兩時做+被罵)

Productivity is useful for: 1. internal comparison among different periods to measure efficiency (值得整某餸), 2. external comparison with other ppl (廚娘界競爭力). meals per labor hour