Supermarket

Kanban System and supermarket

Kanban

A kanban (Japanese word) card is a card holding informations related to packaging of product(s) to wich it is associated. To keep it simple, will take an example where package contains a single product, allowing us to associate kanban information directely with product.

Rules:

• Every product comming out of fabrication is associated to a kanban card and conversely

• A product is manufactured only to be associated to a kanban card, meaning if no stand alone kanban cards is waiting for its product, no manufacturing!

• A kanban card is physicaly located on the product, or waiting for it at production. Corrolary: if a kanban card is not in front of the machine, it's on the product.

• Consummer picking a product leaves the kanban. This isolated kanban become an order for a new product to replace the one wich was just picked up.

Kanban system

1. No kanban in front of machine means no order, so no production.

2. Kanban(s) in front of machine means as many orders than kanban cards, so production is required for equivalent quantity.

3. As soon as a product is manufactured, kanban is associated.

If many kanban cards wait in front of machine, it means equivalent number of products have been picked-up by consummer. It is time to manufacture the same quantity of products.

The supermarket

The consummer just picked up goods in the supermarket. He takes only products away, kanban cards stay. For stock manager (sometimes machine's operator directely), an isolated kanban "calls" a product to be associated and refill the stock.

In practice, a supermarket contains several references. The stock manager goes checking regularly the status of supermarket shelves. He picks all kanbans and transmits them to fabrication. Production understands order status and manufactures accordingly.

Vending machines are a pretty good example of supermarket system.

The slots (number of rows in front and places in depth) are set accordingly to sales (consumption).

Fast movers (most sold products) will get more slots than slow movers (least sold products), in order to minimize lost sales for shortage between two refillings.