This chapter described the model for Discrete Manufacturing—that is, the manufacturing of products (Discrete Items) that can be counted.
This is as opposed to Process Manufacturing, which produces chemicals. That is described more fully in Data Model Patterns: Conventions of Thought.
Here we learned about the Routing Elements that describe the structure of the manufacturing process and the Work Orders that drive it. As it happens, the structure of the manufacturing effort is very similar to that for maintaining the equipment involved. Indeed, your author had the opportunity to study a nuclear power plant and discovered that no one there produced electricity. They were entirely devoted to maintaining (ok, and operating) the equipment ...