What is needed is just the courage to face inconsistencies and to avoid running away from them just because “that’s the way it was always done”. - Eliyahu M. Goldratt

[Throughput is the] rate at which the system generates money through sales.

Flow means that inventories in the operation are moving. When inventory is not moving, inventory accumulates. Accumulation of inventory takes up space. Therefore, an intuitive way to achieve better flow is to limit the space allowed for inventory to accumulate. To achieve better flow, Ford limited the space allotted for work-in-process between each two work centers.

Well, since we started keeping data on the bottlenecks, I’ve been noticing I’m able to predict several weeks in advance what each bottleneck will be working on at a particular time. See, as long as I know exactly what’s in queue, I just take the average setup and process times for each type of part, and I’m able to calculate when each batch should clear the bottleneck. Because we’re only dealing with one work center, with much less dependency, we can average the statistical fluctuations and get a better degree of accuracy.