Demand windows are periods of time when customer demand is relatively stable. For slow growth or mature products, the window can be extremely long.

For other products, demand windows can change seasonally (think water skis or snow shovels), hour-by-hour (think fast food), or can trend steeply up or down.

In Lean, demand is used to calculate takt time, which in turn drives capacity planning. That capacity is only relevant in the proper demand window.

In the case of cyclical demand, managers need to plan how to rapidly switch production to match each demand window without driving up production costs.

When the demand is trending, either up or down, managers must plan how to switch capacity when one demand window closes and another demand window opens.

Demand Windows