the one that can give you the best delivery and product quality at the lowest possible cost.

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 tight answer, the one that can give you the best delivery and product quality at the lowest possible cost. To find the 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.

What is important is the thinking you force yourself to go through to understand the relationship between the various aspects of your production process.