Kanban

Definition

In Japanese, means "Relay Baton" (in the sense relay course).

Created in the 1970s, by the car manufacturer Toyota, the Kanban system is a tool contributing to the "Just in time” process. Its main objective is to reduce stocks. It is particularly useful in big series manufacturing processes.

Working on a pulled flow principle (the customer "calls for" the product), the first step is to define the ideal quantity of products to be delivered, neither too small to allow the production to run smoothly, nor too big to reduce stocks.

We attach a label: Kanban, to this quantity (one packaging with parts, for example). When the "customer" consumed this packaging, the Kanban label is sent back to the "supplier" and acts as a manufacturing order for him. During this time, the "customer" consumes another packaging which was supplied in the same way, and this continuously. It allows a reduction of stocks.

Requirements for Kaban system

• Irreproachable deliveries on behalf of the "supplier".
• Short and reliable "supplier" leadtimes
• The "customer", as well as the "supplier" has to work without security stock.
• The production must be in large series with few fluctuations
• The quantity of Kanban labels must be regulated: neither creations, nor losses.

Information of Kaban

• Kanban serial number.
• Product’s reference.
• "Customer" references: name, address.
• "Supplier" references: name, address.
• Packaging type
• Quantity of references by packaging.

How to size the quantity of Kanbans labels

         C*D + S

Number of Kanbans = -----------

                                                   Q

Where:

• C: Average reference Consumption
• D: Delivery Leadtime (since the departure of Kanban from "customer" site until the arrival of the product at the "customer")
• S: Safety margin (< 10 % of CxD)
• Q: Quantity of references by chosen packaging