Kanban (literally signboard or billboard) is a scheduling system for lean and just-in-time (JIT) production. Kanban is a system to control the logistical chain from a production point of view, and is not an inventory control system. Kanban was developed by Taiichi Ohno, at Toyota, to find a system to improve and maintain a high level of production. Kanban is one method through which JIT is achieved.
Kanban cards are a key component of kanban and signal the need to move materials within a manufacturing or production facility or move materials from an outside supplier in to the production facility. The kanban card is, in effect, a message that signals that there is a depletion of product, parts, or inventory that, when received, the kanban will trigger the replenishment of that product, part, or inventory. Consumption therefore drives demand for more production, and demand for more product is signaled by the kanban card. Kanban cards therefore help create a demand-driven system.