Three Bin System

The three-bin system is a Kanban-based replenishment method where one bin sits at the point of use, a second in an internal buffer, and a third at the supplier. When the first bin empties, its return triggers replenishment from the second, and that consumption triggers supplier dispatch from the third.

On the shop floor, operators draw parts from a line-side bin until it empties. The empty bin or its Kanban card travels back to the stockroom, authorizing release of a full bin from the second storage point. That release keeps production moving without relying on plans or forecasts. Meanwhile, the stockroom’s depletion signals the supplier to dispatch the third bin from a reserved location. Each bin carries identity, quantity, and tracking data, so every worker knows which material to move, when to move it, and who owns the next action. This setup works best for repetitive raw materials and controlled-flow parts where continuity matters more than bulk stocking. It creates a pull loop that reduces overproduction, protects against short-term demand spikes, and absorbs transport or receiving delays. Every line-side bin is always backed by one internal buffer and one supplier buffer, sustaining production when downstream replenishment is slower than normal.