Kanban Cards
IMPLEMENTING LEAN
Using Kanban Cards
A Kanban Card is a visual signal to help you manage inventory of stock, supplies and materials. On the Kanban card you will find basic information such as the minimum level of a particular item. Once this level is reached, the Kanban card should be “pulled”, and the stock re-ordered.
It is a very basic way of knowing when to restock something. By including the minimum level for an item, it can also serve as a visual guide for how many is the minimum amount. The minimum level also helps during the re-stocking process, as the Kanban can be placed back in the correct position.
The Kanban card can be as detailed or as sparse as required. Some Kanban cards may feature the following details:
Part Name / Description
It is important to know what item the Kanban is referring to.
You may use the name of the item, a brief description, or ideally a SKU.
Minimum Number / Amount
This is the most basic requirement of a Kanban Card.
It not only tells the person when to “pull it” and start the re-ordering process, but also where to place the Kanban Card at the time of restocking.
If the minimum is 2 of a particular item, when 5 are ordered and delivered, the card should be placed in a way that indicates 2 is the minimum
Item Photo
A very visual way of ensuring that the right card is “pulled” and the person re-stocking it knows exactly what the part is.
Where to Restock From
This could be an internal item being produced, or something you buy online.
Letting people know where it is re-ordered from is handy for the person actually doing the purchasing process.
Even better would be to provide a link to the exact item. This is Poka-Yoke as it reduces the likelihood of the wrong item being purchased. It also reduces the time spent looking for the item.
Where to Deliver the Card to
When the kanban card is “pulled”, you need to know where to take it to be re-ordered or remade.
Telling the operator exactly who or where to take the card will remove ambiguity and wasted time.
How Many to Order
Again, useful for the person re-ordering the item to avoid any ambiguity or guesswork on how many to purchase.
Item Location
This is useful for the person re-stocking the goods as they know exactly where to take the goods to restock them.
An advanced method is to use QR codes on the Kanban Cards themselves. When the Kanban is pulled, you can scan a QR code which can send an email or SMS to the purchasing department. Here you can include web links, quantities and much more.
Example
The toy factory needs to keep a stock of red spray paint for painting their toy cars.
The Setup
They typically keep 6 cans in stock at any one time, but the minimum is 2.
On the shelf where they keep the paint, 2 bottles are tied together with an elastic band.
There is a Kanban Card stuck to these two bottles.
Once the 4th can has been used, the reserve stock must be used.
“Pulling” the Kanban and Re-ordering
4 cans have been used, meaning they now need to use the first can from the reserve stock.
The Kanban Card is “pulled” as they are now below the minimum threshold.
The card has instructions to take it to the office, so the operator delivers the card there.
The cans are re-ordered, and delivered two days later.
The Re-stock
On arrival at goods-in, the Kanban is married up to the product and returned to the re-stock location.
The person who is re-stocking knows that 2 is the minimum number based on the writing on the Kanban so knows where to put the Kanban.
These steps will repeat over and over again to keep stock of the red spray paint. There is initial labour in setting up the Kanban card and the stock location. Once this is done though, with a strong enough Standard Operating Procedure, the factory should never run out of red spray paint again.
