KANBAN method: 4 steps inventory control system

Discover the KANBAN method, zero break, zero over-stock.

TRAINING THROUGH GAMES FOR THE METHOD KANBAN

Sizing and controlling stocks with the Kanban method

Continuous improvement in the supplier-customer relationship is essential to maintaining close and lasting partnership relationships. Improving inventory management as necessary ensures maximum flexibility and service. The Kanban method is designed to facilitate these improvements in industry.

IMPROVING STOCK MANAGEMENT AS NECESSARY

Principle of the Kanban System

 
 

Kanban is a form or card that accompanies each batch of coins. This simple "piece" of paper in a Kanban system becomes an indispensable visual signal to indicate when and how much to produce.

The kanban card contains 3 types of information:

Identification information

Part reference and number of pieces per container, possibly photo of the part.

Tracking Information

Customer's and supplier's identification, where to store the containers and where to place the released kanban master records.

Management Information

Number of KANBAN labels in circulation for the reference and the release lot size. This will make it easy to check that the KANBAN loop put in place is helping to reduce stocks.

A KANBAN loop is the circuit followed by the Kanban cards. For a given reference, it is the set of Kanban cards required and sufficient to ensure the continuity of supply to the customer by his supplier. KANBAN organizes production in pull flow : The customer is downstream and controls the supplier's production upstream.

This means that it is the sales orders that automatically trigger the production of parts by feedback of the orders from the exit of the products. There are two types of kanban, the production kanban and the transfer or delivery one.

Origin and interest of the Kanban method


The KANBAN method has appeared in Toyota factories. Many methods such as the 5S method, or TPM, come from Toyota factories, called TPS (Toyota production Systems). It is Taiichi Ōno, a Japanese engineer, the precursor of this production management method. Outside the industry the Kanban method is also a project management system just like the Agile method or the Scrum method..

This production system can be applied in any part of the flow, i.e. :

   Between two workshops or two machines
  Between a store and a manufacturing workshop
  Between a production site and its suppliers

The Kanban system enables production to be controlled using a visual system that generates production orders that meet actual consumption. A simple and permanent customer-supplier relationship is established.
The stock is kept under control because it is kept within a range that makes it possible both to ensure deliveries and to avoid breakdowns or overruns.
The KANBAN method is well adapted to large and medium series whose flow has been regulated. With a few adaptations, it can also be applied to small series.

It can become the essential tool for progress to which other improvement actions can be added, focusing on:

 The flexibility of the means of production within the framework of a SMED approach
  Improving their reliability as part of a TPM approach
  The development of the skills of operational actors such as line coordinators, operators...

The Kanban method, a LEAN Manufacturing tool

Purpose of the Kanban method

 
 

It is often thought that stocks enable to ensure deliveries despite machine breakdowns, despite defects and errors of all kinds, despite imbalances in production lines.
This convenience always comes at a high price. While the effects of malfunctions are mitigated by inventories, the cost of these anomalies is not. Worse, the feeling of security given by the stock induces a laxity in the exploitation of resources, which always leads to a drift in production costs. Stocks mask real production problems. They are also a powerful inhibitor of progress.

Sesa Systems character with cardboard boxes to permanently manage the results obtained thanks to the takt Time of the Hoshin method

Seeking to constantly lower stock levels means committing to a continuous improvement process whose sole objective is the elimination of hazards that disrupt production and increase production costs. For a supplier, the basic rule is to produce only the quantity of compliant parts the customer needs, when he needs them and with a reasonable level of stock. For that, the application of the Kanban supports the realization of this objective.

Kanban, a Japanese term meaning "label", is a method of controlling the flow of materials based on the flow of information exchanged between a customer and his supplier. It allows:

  To optimize production by allowing the supplier to deliver only what the customer requires, i.e. in pull flow. In this case stocks are reduced to the bare minimum.
  Simplify and strengthen relationships between customers and suppliers at all stages of manufacturing by shortening information circuits.
  To delegate to manufacturing the scheduling of the fabrications made simple, visible and reliable.

SESA SYSTEMS character with Kanban sheet for production quality monitoring

The Kanban method enables to reduce

Inventories and work in progress thanks to an organization

The storage surface by the installation of a Kanban loop

Malfunctions by precise rules

Example of the method with a kanban board


Kanban method using an inventory management table

A Management Approach with the Kanban Board


The Kanban method decentralizes and simplifies production management within the production area. There is no longer any need for production orders, the KANBAN visual system is self-managing thanks to direct decision-making at the operator level. All thanks to a visual inventory tracking chart. Especially because this visual table groups together the kanban labels awaiting production. It is therefore placed close to the supplier. A management table has as many columns as there are references. Each column must be sized according to the number of cards in the loop. The choice of media is determined according to the user's needs. The implementation of a visual Kanban management board provides:

  Real-time tracking of product quantity

  Quick and easy visualization

  An improvement in stock rotation and work team autonomy

SOME RULES TO FOLLOW TO OPTIMIZE YOUR KANBAN

 

KANBAN's operation can only be reliable if a few simple rules are scrupulously respected by everyone involved in the circulation of labels. First of all, a card is attached to each full container and the customer releases the KANBAN card as soon as he consumes the container to which he is attached. The containers strictly contain the quantity of parts indicated on the label. The customer then returns the master records to the vendor as soon as they are released. Free KANBAN forms must appear on the tracking chart.

For a constant consumption of products by the customer, it is common to colour the KANBAN areas to make them visual. The manufacturing process is started by observing the management chart. The successive attainment of the thresholds determines the priority to be manufactured. The KANBAN management board, visible to all, allows you to know exactly the customer's consumption and to commit the right resources in time to supply it. There are also methods for calculating its thresholds.

How the FIFO System Works with the Kanban Method

Green field (good threshold): This is the minimum release lot size. When KANBAN cards are in this area, production start is not allowed.

Orange or yellow zone (threshold limit): It is located between the green and red zones. It is a "buffer" zone that absorbs fluctuations in downstream load and supplier contingencies. It also makes it possible to arbitrate priorities between the different references. When the badges are in this area, it is possible to start production.

Red zone (alert threshold): When the queue reaches this zone, production must be started as a matter of urgency because a supply disruption at the customer's premises is possible. In the red zone, the supplier must contact his customer to inform him of the difficulties he is encountering. This safety zone makes it possible to absorb the hazards and the strong fluctuations of the demand.

In some cases, it is imperative to respect the FIFO rule, i.e. first in-first out (product freshness, material expiry, quality maintenance). In all cases, it is strongly recommended.

To go further


ESSENTIAL TOOLS TO PERPETUATE THE KANBAN METHOD

SESA SYSTEMS creations for the creation of a Kanban project