Complexity and Ashby's Law

Ashby's Law concerns the relationship of a control system to the system it attempts to control. One version of Ashby’s Law is in the box at right. Ashby’s Law tells us that a complex system requires a complex controlling device. Conversely, simple systems require only simple controllers for successful operation.

The implication for for Lean Manufacturing is that we should first simplify the process. That does not mean that the process technology of each operation must be simple; only that the number of steps, the material paths and the number of variations that affect the inventory should be simple.

Cellular layouts simplify processes. They organize work around a product or a narrow range of similar products. Materials sit in an initial queue when they enter the cell. Once processing begins, they move directly from process to process. Notice the simplicity of material flow. Scheduling, supervision and many other elements illustrated below.