“Because each alternative costs money, your task is to find the most cost-effective way to deploy your resources—the key to optimizing all types of productive work. Bear in mind that in this and in other such situations there is a right answer, the one that can give you the best delivery time and product quality at the lowest possible cost. To find that right answer, you must develop a clear understanding of the trade-offs between the various factors—manpower, capacity, and inventory—and you must reduce the understanding to a quantifiable set of relationships.”