Kanban - what is it? The principle of lean manufacturing

Kanban - what is it? How much interesting information does the kanban map contain, and what function does the method perform in production? In the article, we will explain in detail the rules for the effective application of kanban, and also give a vivid description of the scheme of using the corresponding maps for a specific example. In addition, after getting acquainted with the material, you will find out why the kanban board is needed, in which areas, in addition to production, it is advisable to apply this method, and that can serve as a good alternative to it.

The essence of the concept and the main features of the method

Today, one can observe a bright tendency to increase the cost of storing stocks, which is the main reason for the formation of complexes of "instantaneous" management of them, which includes the kanban system. In Japanese, "kanban" means "tag", "badge". This term serves as a method of informing, through which permission is given or an indication of the production or exclusion (transfer) of a product in a pulling system.

The presented variant of the information delivery allows to fully manage lean production lines through the use of information cards for the transfer of a certain order for manufacturing with a subsequent step to the previous one.

The developer of such a productive system is Toyota Motors, which explains the presented idea as one of the first attempts to implement the method "just in time". According to the kanban system, production is carried out in accordance with the following rule: the enterprise subdivisions are supplied with resources in a specific quantity and to a clearly defined period necessary for the fulfillment of the order.

Process Details

The scheme of the presented method is extremely simple, nevertheless it has a very effective effect on the organization of the production process. After supplying the enterprise units in resource terms, a detailed calculation of the required amount of work in progress is made, which should come directly from the penultimate stage (the order for the finished product, respectively, is the final stage of the process). Similarly, from the penultimate stage, a request is made for the previous stage for a specific volume of semi-finished products.

Thus, the scale of production in a certain area is formed in accordance with the needs of the next production stage. It is logical that between the two stages of the production process, located in the neighborhood, a double type of connection is established:

1. From the n-th stage, the required amount of work in progress is requested ("drawn out") by n-1.
2. From the n-th stage, the n-th resources are directed to the material resources in the required volume.

Communication tools

To understand better, kanban - what it is, it should be understood that special information cards are used in this system to transfer information, which are classified into two groups:

1. Tools that are directly relevant to the production order. In such cards, the number of parts that must be produced in the previous stage of the production process is indicated in the first place. They are sent from the n-th stage of production to the stage n-1 and serve as the main reason for developing the production program of these sites.
2. The selection tools contain information on the amount of material resources required (semifinished products, materials, parts, etc.) that must be taken at the previous stage of assembly. Such cards display the resource volume, in fact received by the n-th stage of the production process from n-1-st.

It is important to note that cards can circulate not only with respect to the internal infrastructure of the enterprise, but also between its branches or corporations that support cooperation.

Effective methods of using kanban - what is it?

Taiichi Ono, president of Toyota Motor Corporation, has developed a set of principles that make it possible to use kanban cards with maximum efficiency:

• The subsequent operation with respect to production activities removes the amount of detail indicated by the card from the previous operation.
• The production operation in front is carried out in accordance with the creation of parts in the quantity and sequence that is indicated in the specific card.
• There are no such details that can be created without a card. This provision allows to ensure a reduction in overproduction, as well as excessive movement of products. Thus, the volume of cards in circulation is equivalent to the maximum number of stocks.
• A card is an order for the production of a product (the product in any case is attached to the corresponding card).
• Parts that have a defect can not be transferred to a subsequent process. This provision makes it possible to make products as defect-free as possible.
• Reducing the number of cards increases the level of their sensitivity. So, outside the existing problems are emerging and effective control is being carried out with respect to stocks.

Features of the application of cards

As it turned out, the management of kanban is carried out according to a certain scheme, which involves the use of special cards. So, in the course of their application, the requirements for absolute visibility and ultimate safety of the system in question should be fully implemented: the loss of cards, as well as their mixing, is completely excluded.

Specialists have developed an effective tool that allows to give maximum productivity to the kanban system. The board of this method serves as a place for collecting active cards, because so often in the workplace employees use several different tools. Thus, the cards that stay with the manufacturer are placed on the control board. And when the newly received card tools reach the "launch" field, the whole set of cards of the corresponding part number is transferred for the further production process.

Advantages of applying the kanban method - what is it?

Enterprises that use the CANBAN system receive daily supplies of material resources (and often several times throughout the day). This allows you to fully update production stocks approximately 100-300 times during the year. If you compare kanban with systems such as MRP or MAP, then in the case under consideration an update is approximately 10 times more frequent.

Suitable examples for assessing the kanban method are examples that reveal its absolute superiority over others, less productive. So, the corporation Toyota Motors on one of a set of sites of manufacture in 1976 supplied resources three times a day, and in 1983 - already every ten minutes.

Often kanbans are used in working with supermarkets (specially formed for this stock). So, the consumer sends to the supermarket kanban selection, which indicates, as noted above, the volume of the product, and the supermarket gives him a specified number of products. At the same time, the supermarket sends a supply kanban towards the supplier, after which the supplier transfers the products to the supermarket.

Fundamental elements of the method

The most important components of the kanban system are the following:

1. Information complex, which contains in its structure not only cards, but also production, transport or supply charts, as well as technological maps.
2. The complex, which is directly related to the control over the needs and rotation of personnel in a professional manner.
3. Complex that allows to implement universal (TQM) and selective ("Jidoka") product quality control.
4. Complex, which realizes the absolute equalization of production.

The presented elements, applied in aggregate, allow to achieve the shortest production cycle, a high level of asset turnover (including inventories), and also to exclude or minimize the costs of storing both production and commodity stocks and, of course, to reach the highest Quality of the product at each stage of the production process.

The disadvantages of the system and the results of its application

Like any development, the system "just in time" is endowed with some disadvantages. First, it is the complexity of organizing a high level of consistency between the stages of production of a particular product.

Secondly - a significant risk of disruption of the production process, respectively, and the sale of products. Nevertheless, a detailed analysis of the world practice with respect to the application of the method under consideration showed that the presented system makes it possible to reduce production reserves by half, and commodity ones by 8%, with a significant acceleration in the turnover of circulating assets and, of course, an improvement in the quality of the finished product.

It is important to note that the use of kanbans does not end in production processes. So, the system is actively used in office and project activities, in programming (there is a whole complex of kanban development), and also in achieving personal results (personal type of kanban).