The Kanban SystemOne of the most pu

The Kanban SystemOne of the most publicized aspects of lean systems, and the TPS in particular, is the kanban system developed by Toyota. Kanban, meaning “card” or “visible record” in Japanese, refers to cards used to control the flow of production through a factory. In the most basic kanban system, a card is attached to each container of items produced. The container holds a given percent of the daily production requirements for an item. When the user of the parts empties a container, the card is removed from the container and put on a receiving post. The empty container is then taken to the storage area, and the card signals the need to produce another container of the part. When the container has been refilled, the card is put back on the container, which is then returned to a storage area. The cycle begins again when the user of the parts retrieves the container with the card attached.Figure 6.9 shows how a single-card kanban system works when a fabrication cell feeds two assembly lines. As an assembly line needs more parts, the kanban card for those parts is taken to the receiving post, and a full container of parts is removed from the storage area. The receiving post accumulates cards for assembly lines and a scheduler sequences the production of replenishment parts. In this example, the fabrication cell will produce product 2 (red) before it produces product 1 (green). The cell consists of three different operations, but operation 2 has two workstations. Once production has been initiated in the cell, the product begins on operation 1 but could be routed to either of the workstations performing operation 2, depending on the workload at the time. Finally, the product is processed on operation 3 before being taken to the storage area.