| What is kanban?
A system of continuous supply of components, parts and supplies, such that workers have what they
need, where they need it, when they need it.
The word Kan means "card" in Japanese and the word "ban" means "signal". So Kanban refers to "signal cards".
Here's how Kanban works :
Let's say one of the components needed to make widgets is a 42'' stem-bolt and it arrives on pallets. There are 100 stem-bolts on a
pallet. When the pallet is empty, the person assembling the widgets takes a card that was attached to the pallet and sends it to the stem-bolt manufacturing
area. Another pallet of stem-bolts is manufactured and sent to the widget assembler.
A new pallet of stem-bolts is not made until a card is received.
This is Kanban, in it's simplest form.
A more realistic example would probably involve atleast two
pallets. The widget assembler would start working from the second pallet while new stem-bolts were being made to refill the first pallet.
If this was a high volume widget manufacturing
facility, each widget assembly station might empty a pallet of stem-bolts in just a few
minutes, and there could be 15 or 20 widget assembly
stations. Thus there would be a continual flow of cards going back to the stem-bolt manufacturing area that would cause a continual flow of pallets stem-bolts to be sent to the widget assembly stations.
Kanban is Pull (Demand):
This is called a "pull" type of production system. The number of stem-bolts that are made depends on the customer demand-in other words the number of cards received by the stem-bolt manufacturing area.
Systems other than cards may be used. For example the empty pallets may be returned to the stem bolt manufacturing
area. Each empty pallet received indicates a need to manufacturing 100 more stem
bolts. For other types of components, bins, boxes or cages might be used
instead of pallets. or components might be stored on shelves in the widget assembly area. When a shelf became empty that signals that more components need to be manufactured and the shelf refilled.
In kanban the method of handling the components is flexible, and depends on the needs of the manufacturing process.
An Alternative Kanban Model:
kanban can also operate like a supermarket. A small stock of every component needed to make a widget would be stored in a specific location with a fixed space allocation for each
component. The widget assemblers come to the "supermarket" and select the components they
need. As each component is removed from the shelf, a message is sent to a "regional warehouse" or component manufacturing facility, requesting that the component be replaced. The "supermarket" might then receive a daily shipment of replacement components, exactly replacing those that were used.
If we just change the term "supermarket" to "warehouse" we have our manufacturing example.
The "supermarket" model is
different from the first Kanban example in that it would be used when components are manufactured in facilities that are distant from the widget assembly plant. Instead of moving around small quantities of components, larger quantities are shipped once a day to the centralized warehouse.
JIT - Just In Time/ Continual Improvement
Kanban is directly associated with Just - In - Time (JIT) delivery. However Kanban is not another name for just - in -time delivery. It is a part of a larger JIT system. There is more to managing a JIT system than just Kanban and there is more to Kanban than just inventory management.
For example,kanban also involves industrial re-engineering.
This means that production areas might be changed from locating machines by function, to creating "cells" of equipment and
employees. The cells allow related products to be manufactured in a continuous flow.
Kanban involves
employees as team members who are responsible for specific work
activities. Team and individuals are encouraged participate in continuously improving the Kanban
processes and the overall production process.
Kanban is not a system indented to be used by itself. It is an
integrals part of Kaizen and 5S.
Getting Started With Kanban
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