Kanban System

 The work kanban literally means visual record usually kanban is loosely referred to as a card system. Kanban is the production control system that pulls JIT production allowing production with smaller inventories.

Two card kanban : In the Toyota production system for example inventory is closely controlled at low levels by suing a manual two card knaban system. One kind of card the conveyance kanban is similar to a requisition and authorizes the transference of materials from a supplying work centre to a using work centre. A second card the the production kanban authorizes the production of materials to replace those that ware transferred earlier.

Materials are transferred and produced in bins and for each item in the production process are a prescribed number of bins in circulation at any one time. In addition each bin houses a prescribed quantity say four units of materials. By choosing the number of bins and the prescribed quantities in them inventories are carefully and visibly controlled on the shop floor. By reducing the number of card circulating between two interacting work centers in process inventories approach zero and the needed parts, or final products do not exist. Stockless production is a major feature in the pull system of planning and control.

Single card Kanban : In contrast to the two cards systems a single card kanban system uses only a conveyance ( or move) kanban and no production kanban. While Toyota and a few other companies use the two card system single card kanban is the most often used.