productivity is the act of bringing a company closer to its goal. Every action that brings a company closer to its goal is productive. Every action t… - Eliyahu M. Goldratt

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.

We need financial measurements for sure — but we don’t need them for their own sake. We need them for two different reasons. One is control; knowing to what extent a company is achieving its goal of making money. The other reason is probably even more important; measurements should induce the parts to do what’s good for the organization as a whole.

Throughput,” he says, “is the rate at which the system generates money through sales.