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 use of kanban, as well as give a vivid description of the use of the appropriate cards using a specific example. In addition, after familiarizing yourself with the material, you will know why a kanban board is needed, in which areas, in addition to production, it is advisable to use this method, and what 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 vivid tendency to increase the cost of storing stocks, which is the main reason for the formation of complexes of "instant" management of them, which includes the kanban system. Translated from Japanese, "kanban" means "tag", "badge". This term serves as a method of informing by which permission is given or an indication of the production or exclusion (transfer) of the product in the drawing system.
The presented information delivery option allows you to fully manage lean production lines by using information cards to transfer a specific manufacturing order from the next step to the previous.
The developer of such a productive system is Toyota Motors, which explains the idea presented as one of the first attempts at the practical implementation of the “on time” method. According to the kanban system, production is carried out in accordance with the following rule: enterprise units are supplied with resources in a specific quantity and by a clearly defined time period required to complete 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’s departments in terms of resources, a detailed calculation of the required volume of work in progress is carried out, 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 amount of semi-finished products.
Thus, the scale of production at a certain site is formed in accordance with the needs of the next production stage. It is logical that between each two stages of the production process located in the neighborhood, a double type of connection is established:
- From the n-th stage to n-1, the required amount of work in progress is requested ("pulled").
- From the n-1st stage to the n-th, resources of a material nature are sent in the right amount.
Information Transfer Tools
In order to better understand kanban - what it is, it should be understood that special cards, which are classified into two groups, serve as a tool for transmitting information in this system:
- Tools directly related to the production order. In this kind of cards, first of all, the number of parts to be produced at the previous stage of the production process is indicated. They are sent from the n-th production stage to the n-1 stage and serve as the main reason for developing the production program for these sites.
- Selection tools contain information regarding the amount of necessary material resources (this can include semi-finished products, materials, parts, etc.) that should be taken at the previous stage of assembly. This kind of card displays the resource volume, in fact, obtained by the n-th stage of the production process from the n-1st.
It is important to note that cards can circulate not only in relation to the internal infrastructure of the enterprise, but also between its branches or corporations that support cooperation.
Effective Kanban Uses - What Are They?
Tayichi Ono, president of Toyota Motor Corporation, has developed a number of principles that allow you to use kanban cards with maximum efficiency:
- The subsequent operation in relation to production activity withdraws the volume of parts 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 on the specific card.
- There are no such parts that can be created without a card. This provision allows for the reduction of overproduction, as well as excessive movement of products. So, the volume of cards in circulation is equivalent to the maximum number of stocks.
- A card is an order for the manufacture of a product (the product is attached in any case to the corresponding card).
- Parts with any defect cannot be transferred to a subsequent process. This position allows to make the release of products as defect-free as possible.
- Reducing the number of cards increases their sensitivity. So, the existing problems come out and effective control is carried out in relation to stocks.
Features of the use of cards
As it turned out, kanban control is carried out according to a certain scheme, which involves the use of special cards. So, in the course of their application, the requirements to ensure absolute visibility and maximum safety of the system under consideration should be fully implemented: the loss of cards, as well as their mixing, is completely eliminated.
Experts have developed an effective tool to maximize the productivity of the kanban system. The board of this method serves as a place to collect active cards, because so often at the workplace employees use several different tools. Thus, the cards that arrive at the manufacturer are placed on the control board. And when the newly arrived card tools reach the “launch” field, the entire set of cards of the corresponding part number is transferred for the further production process.
The benefits of using the kanban method - what is it?
Enterprises that use the CANBAN system carry out daily supply of material resources (and often several times during the day). This allows you to fully update inventories approximately 100-300 times during the year. If we compare kanban with systems such as MRP or MAP, then in this case, the update occurs about 10 times more often.
Examples are useful for evaluating the kanban method, revealing its absolute advantage over other, less productive ones. Thus, Toyota Motors Corporation supplied resources to one of the many production sites three times a day in 1976, and in 1983 every ten minutes.
Often, kanbans are used in working with supermarkets (specially formed stock for this). So, the consumer sends the kanban of selection to the supermarket, where, as noted above, the volume of the product is indicated, and the supermarket gives him the specified number of products. At the same time, the supermarket sends replenishment kanban towards the supplier, after which the supplier transfers the products to the supermarket.
Fundamental elements of the method
The most important components of a kanban system are:
- The information complex, which contains in its structure not only cards, but also schedules of a production, transport or supply nature, as well as technological maps.
- A complex that is directly related to the control of needs and staff rotation in a professional manner.
- A complex that allows for universal (TQM) and selective ("Jidoka") product quality control.
- A complex that implements absolute production equalization.
The presented elements, used together, can achieve the shortest production cycle, a high level of asset turnover (including inventory), as well as eliminate or minimize the cost of storing both production and inventory and, of course, achieve the highest product quality at each stage of the manufacturing 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. Firstly, it is the complexity of organizing a high level of consistency between the stages of production of a product.
Secondly - a significant risk of disruption of the production process, respectively, and the sale of products. Nevertheless, a detailed analysis of world practice regarding the application of the method under consideration showed that the presented system makes it possible to reduce production inventories by half, and inventories - by 8%, with a significant acceleration of working capital turnover and, of course, improving the quality of the finished product.
It is important to note that the use of kanban 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), as well as in achieving personal results (personal type of kanban).