Kanban is a tool to achieve production of the JIT (just in time). It is a card that is usually placed on rectangular vinyl envelope. Two commonly used types of kanban yanmg: kanban demand (withdrawal kanban) and kanban production orders (production-ordering kanban). Kanban request specifies the type and number of products where a further process must request from the previous process, while the production ordering kanban specifies the type and amount of product from the previous process ynag must be produced. Production-ordering Kanban is often called in-process Kanban or simply kanban production.
Kanban other types also exist. To make a request from the vendor / supplier, used kanban supplier (supplier kanban). Kanban dealers dealer containing instructions subcontracting request which will deliver spare parts. Furthermore, to specify the production lot in diecasting, punchpress, or forging process, a kanban signal is used. There are two types of kanban signals, namely: Triangular, and kanban kanban kanban prosecution material. Triangular Kanban is made of metal and quite heavy, medium-kanban material prosecution specify point-re-ordering of material needs.
Kanban RulesTo realize the purpose of the kanban JIT, the following rules must be followed:
1. The process continued to draw the necessary product of the previous process in the required amount of time required.
The successful application of this rule relies on the guarantee of workers that the system is useful and easy to administer. This rule will probably be found with many obstacles because it requires a complete change from the previous production system.
Subaturan which become part of this rule are:o Any withdrawals without going through the kanban should be bannedo Any withdrawals are greater than the number of kanban lenih should be bannedo A kanban must be attached to the physical product.
Smoothing of production or increase daily production, are necessary conditions for a withdrawal and small-lot production of a continuous process, and most important is to apply the rule 1. Smoothing of production, for example: only if diterpakan kanban system to attract foreign subcontract parts of the company, then the kanban is a very dangerous weapon and uses the original will be lost. Subcontractors need of supplies, equipment, and manpower in large numbers to respond to fluctuating demand from manufacturers.However, even if a rule is applied, JIT production can not easily be achieved because the kanban system is simply a tool dispatching to the actual production activities every day in every process. Before entering the phase of dispatching jobs with kanban, the overall planning of the entire plant must be made in advance.
2. Previous process must produce their products in the amounts withdrawn by the next processWhen the kanban rules 1 and 2 were observed, all of the production process so that it becomes a kind of combined transport lines. Balancing of production time on all processes will be maintained by strictly observing the rules. If a problem arises in any process, the whole process may stop, but the balance between the processes is maintained. Therefore, the Toyota production system is a structure to realize an ideal transportation lines and kanban as a tool that connects all the processes. As a result, inventories are kept by each of the previous process will terminimisasi. Subaturan for the second rule is:o The production is greater than the number of sheets should be banned kanbano When the various parts of parts will be produced in the previous process, production must follow the original order in which each type of kanban has been delivered
3. Defective products should never be collected into the next processKanban system that would self-destruct unless all three rules are followed. If some parts found defective, the next process in itself makes the line stops for no extra units of inventory and send the defective part to the previous process. Lines like this dismissal of the next process is very clear and visible to everyone. Also, the operation damaged the withdrawal must be eliminated to ensure rhythmic than the previous process. Standardization of work, therefore, one of the requirements mutalk kanban system.
4. The number of kanban must be minimizedBecause the number of kanban inventory reflects the maximum of the parts, it must be cultivated as small as possible. The total amount of each kanban cultivated fixed. Thus, when average daily demand has increased, lead time should be reduced. This requires reduction of cycle time of standard operating routine with changes in the allocation of labor adjustment.
5. Kanban should be used to adapt the demand of small fluctuationsFitting well with the kanban production refers to the most interesting properties of the kanban system: The ability to adapt to sudden changes in demand or production of an emergency. Companies that do not use kanban system will lack a vehicle to act on it, unexpected changes in demand. Centralized control system used to determine production schedules and issue simultaneous production process, therefore, a sudden change in demand will require at least seven to ten day interval before the schedule can be updated and issued to the factory, the interval time for the computer to compile and calculate the new data. As a result, various production will face disconnection from time to time, mashing the changing needs of production; This issue will form a production process that is less smooth.
Companies that use the kanban system, on the other hand, does not release detailed production simultaneously to the previous process for a month.; Each process can only know what is produced when the production-ordering kanban is released from the container in storage. Only final assembly line receiving circuit for daily production schedule and the schedule is displayed on a computer that specifies that each unit will be assembled next. As a result, although the monthly planning a predetermined requesting creation of six units of A and four B units a day, this comparison can be behind at the end of the day.
Function KanbanKanban functions can be described as follows:1. Induce labor initiatives in the field2. As a means of controlling information3. Controlling inventory4. Adding a sense of belonging among workers5. Simplify management mechanisms work6. Allows management to visually work in the field
Model Kanban
Formula Number of Kanban:(The number of Kanban) = (average demand during lead time) + (safety stock) / (Container capacity)