Why and What is KANBAN

Why use the KANBAN Lean Tool.

"Kan" means “visual”, "Ban" means “signal”. So literally speaking, it means "Visual Signal".

Kanban is an intermediate tool prior to arrive to the "One Piece Flow". It is strongly suggested to use the Kanban and then move to the "One Piece Flow".

Basically is a way to communicate between processes and it helps to establish the "pull" system.

By using the Kanban it is possible to control and stabilize the "work in progress" (WIP) by avoiding one of the seven wastes (overproduction).

Remember that the final scope is to have the "one piece flow"! So, when you have a good Kanban System try to eliminate by moving to the "one piece flow". It is funny is not it ?!

Finally, the Kanban is useful if you have to communicate between distant processes. If you eliminate the distance you do not need Kanban and you have the continuous flow.

What is the Kanban ?

Kanban is a signal to start an action. This action can be a material or product need. It could be even a visual sign for assistance or information request.

What is important to underline is that the signal is always visual and with standard procedures.

The Kanban can be made in different ways:

Everybody in the process have to clearly understand the signal. The procedures activated by a KANBAN have to be defined by people who work in the process. They are the only persons that know the process in detail.

The "Classic Kanban" in the production process is generally organized in this way:

There are 3 bins (or boxes), every bin has its own "Kanban Tag" with information written on that.

1 bin is in the point of use (POU)

1 bin is in the SuperMarket

1 bin is in the Warehouse

When the bin in the POU is empty, that means that they need pieces, the empty bin is moved to the supermarket where it is exchanged with a full bin. Then the supermarket moves the empty bin to the warehouse where it is exchanged with a full bin. The warehouse now has to ask new pieces to the supplier and the cycle is closed.

To implement and let the Kanban works properly you have to follow the 6 rules.

Customer (downstream) processes withdraw items in the precise amounts specified by the Kanban.
Supplier (upstream) produces items in the precise amounts and sequences specified by the Kanban.
No items are made or moved without a Kanban.
A Kanban should accompany each item, every time.
Defects and incorrect amounts are never sent to the next downstream process.
The number of Kanbans is reduced carefully to lower inventories and to reveal problems.