Fundamentally, a manager is looking to answer these questions: ‘what to change?’,’ what to change to?’ and ‘ how to cause the change?’ - Eliyahu M. Goldratt

[Operating expense is defined as] all the money the system spends in turning inventory into throughput.

STEP 1. Identify the system’s bottlenecks. (After all it wasn’t too difficult to identify the oven and the NCX10 as the bottlenecks of the plant.)
STEP 2. Decide how to exploit the bottlenecks. (That was fun. Realizing that those machines should not take a lunch break, etc.)
STEP 3. Subordinate everything else to the above decision. (Making sure that everything marches to the tune of the constraints. The red and green tags.)
STEP 4. Elevate the system’s bottlenecks. (Bringing back the old Zmegma, switching back to old, less “effective” routings. . . .)
STEP 5. If, in a previous step, a bottleneck has been broken go back to step 1.

There are three measurements which express the goal of making money perfectly well, but which also permit you to develop operational rules for running your plant. Their names are throughput, inventory and operational expense.