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In the late 1940s, Toyota started studying [[supermarket]]s with the idea of applying store and shelf-stocking techniques to the factory floor. In a supermarket, customers obtain the specific required quantity at the required time, no more and no less. Furthermore, the supermarket stocks only what it expects to sell within a given time frame, and customers take only what they need, since future supply is assured. This observation led Toyota to view a process as being a customer of preceding processes, and the preceding processes as a kind of store. The customer "process" goes to the store to obtain required components which in turn causes the store to restock. Originally, as in supermarkets, signboards were used to guide "shopping" processes to specific restocking locations.
In the late 1940s, Toyota started studying [[supermarket]]s with the idea of applying store and shelf-stocking techniques to the factory floor. In a supermarket, customers obtain the specific required quantity at the required time, no more and no less. Furthermore, the supermarket stocks only what it expects to sell within a given time frame, and customers take only what they need, since future supply is assured. This observation led Toyota to view a process as being a customer of preceding processes, and the preceding processes as a kind of store. The customer "process" goes to the store to obtain required components which in turn causes the store to restock. Originally, as in supermarkets, signboards were used to guide "shopping" processes to specific restocking locations.

A Kanban system, when combined with unique scheduling tools, can dramatically reduce inventory levels, increase inventory turnover, enhance supplier/customer relationships and improve the accuracy of manufacturing schedules. Kanban aligns inventory levels with actual consumption; a signal is sent to produce and deliver a new shipment when material is consumed. These signals are tracked through the replenishment cycle and bring extraordinary visibility to suppliers and buyers.


Kanban uses the rate of demand to control the rate of production, passing demand from the end customer up through the chain of customer-store processes. In 1953, Toyota applied this logic in their main plant machine shop.<ref>{{cite book|last = Ohno |first = Taiichi |authorlink = Taiichi Ohno |title = Toyota Production System - beyond large-scale production |publisher = Productivity Press |date = June 1988| pages = 25–28 |isbn = 0-915299-14-3}}</ref>
Kanban uses the rate of demand to control the rate of production, passing demand from the end customer up through the chain of customer-store processes. In 1953, Toyota applied this logic in their main plant machine shop.<ref>{{cite book|last = Ohno |first = Taiichi |authorlink = Taiichi Ohno |title = Toyota Production System - beyond large-scale production |publisher = Productivity Press |date = June 1988| pages = 25–28 |isbn = 0-915299-14-3}}</ref>

Revision as of 01:37, 30 January 2013

This article is about the lean manufacturing process. For the software development process, see Kanban (development).
Kanban principles
Kanbans maintain inventory levels; a signal is sent to produce and deliver a new shipment as material is consumed. These signals are tracked through the replenishment cycle and bring extraordinary visibility to suppliers and buyers.[1]
PurposeLogistic control system

Kanban (かんばん(看板)) (literally signboard or billboard) is a scheduling system for lean and just-in-time (JIT) production.[2] Kanban is a system to control the logistical chain from a production point of view, and is not an inventory control system. Kanban was developed by Taiichi Ohno, at Toyota, to find a system to improve and maintain a high level of production. Kanban is one method through which JIT is achieved.[3]

Kanban became an effective tool in support of running a production system as a whole, and it proved to be an excellent way for promoting improvement. Problem areas were highlighted by reducing the number of kanban in circulation.[4]

Origins

In the late 1940s, Toyota started studying supermarkets with the idea of applying store and shelf-stocking techniques to the factory floor. In a supermarket, customers obtain the specific required quantity at the required time, no more and no less. Furthermore, the supermarket stocks only what it expects to sell within a given time frame, and customers take only what they need, since future supply is assured. This observation led Toyota to view a process as being a customer of preceding processes, and the preceding processes as a kind of store. The customer "process" goes to the store to obtain required components which in turn causes the store to restock. Originally, as in supermarkets, signboards were used to guide "shopping" processes to specific restocking locations.

A Kanban system, when combined with unique scheduling tools, can dramatically reduce inventory levels, increase inventory turnover, enhance supplier/customer relationships and improve the accuracy of manufacturing schedules. Kanban aligns inventory levels with actual consumption; a signal is sent to produce and deliver a new shipment when material is consumed. These signals are tracked through the replenishment cycle and bring extraordinary visibility to suppliers and buyers.

Kanban uses the rate of demand to control the rate of production, passing demand from the end customer up through the chain of customer-store processes. In 1953, Toyota applied this logic in their main plant machine shop.[5]

Operation

An important determinant of the success of production scheduling based on demand "pushing" is the ability of the demand-forecast to receive such a "push".

Kanban, by contrast, is part of an approach of receiving the "pull" from the demand. Therefore, the supply or production is determined according to the actual demand of the customers. In contexts where supply time is lengthy and demand is difficult to forecast, the best one can do is to respond quickly to observed demand. This difficulty is exactly what a kanban system can help with: it is used as a demand signal that immediately propagates through the supply chain. This can be used to ensure that intermediate stocks held in the supply chain are better managed (usually smaller). Where the supply response cannot be quick enough to meet actual demand fluctuations (causing significant lost sales), stock building may be deemed more appropriate and is achieved by issuing more kanban. Taiichi Ohno states that to be effective, kanban must follow strict rules of use[6] (Toyota, for example, has six simple rules, below) and that close monitoring of these rules is a never-ending task to ensure that the kanban does what is required.

Kanban cards

Kanban cards are a key component of kanban and signal the need to move materials within a manufacturing or production facility or move materials from an outside supplier in to the production facility.

The kanban card is, in effect, a message that signals depletion of product, parts, or inventory that when received will trigger the replenishment of that product, part, or inventory. Consumption drives demand for more and demand for more is signaled by the kanban card. Kanban cards therefore help to create a demand-driven system. It is widely espoused[citation needed] by proponents of lean production and manufacturing that demand-driven systems lead to faster turnarounds in production and lower inventory levels, helping companies implementing such systems to be more competitive.

Kanban cards, in keeping with the principles of kanban, should simply convey the need for more materials. A red card lying in an empty parts cart would easily convey to whomever it would concern that more parts are needed.

In the last few years, systems that send kanban signals electronically have become more widespread. While this trend is leading to a reduction in the use of kanban cards in aggregate, it is still common in modern lean production facilities to find widespread usage of kanban cards. In Oracle ERP, kanban is used for signalling demand to vendors through e-mail notifications. When stock of a particular component is depleted by the quantity assigned on kanban card, a "kanban trigger" is created (which may be manual or automatic), a purchase order is released with predefined quantity for the vendor defined on the card, and the vendor is expected to dispatch material within lead time.[citation needed] This system is also available in enterprise resource planning software such as Oracle's JD Edwards and eBusiness Suite, IFS AB, Infor ERP LN, SAP ERP, Deltek Costpoint or Microsoft Dynamics AX.[7] [citation needed]

Toyota's six rules

  • Do not send defective products to the subsequent process
  • The subsequent process withdraws only what is needed
  • Produce only the exact quantity withdrawn by the subsequent process
  • Level the production
  • Kanban is a means of fine tuning
  • Stabilize and rationalize the process

Three-bin system

A simple example of the kanban system implementation might be a "three-bin system" for the supplied parts (where there is no in-house manufacturing) — one bin on the factory floor (demand point), one bin in the factory store, and one bin at the supplier's store. The bins usually have a removable card that contains the product details and other relevant information — the kanban card.

When the bin on the factory floor becomes empty (i.e. there is demand for parts), the empty bin and kanban cards are returned to the factory store. The factory store then replaces the bin on the factory floor with a full bin, which also contains a kanban card. The factory store then contacts the supplier’s store and returns the now-empty bin with its kanban card. The supplier's inbound product bin with its kanban card is then delivered into the factory store, completing the final step in the system. Thus, the process will never run out of product and could be described as a loop, providing the exact amount required, with only one spare so that there will never be an oversupply. This 'spare' bin allows for the uncertainties in supply, use, and transport that are inherent in the system. The secret to a good kanban system is to calculate how many kanban cards are required for each product. Most factories using kanban use the coloured board system (heijunka box). This slotted board was created especially for holding the kanban cards.

Electronic kanban systems

Main article: Electronic kanban

Many manufacturers have implemented electronic kanban systems[8] or e-kanban systems. These help to eliminate common problems such as manual entry errors and lost cards.[9] E-kanban systems can be integrated into enterprise resource planning (ERP) systems, enabling real-time demand signaling across the supply chain and improved visibility. Data pulled from e-kanban systems can be used to optimize inventory levels by better tracking supplier lead and replenishment times.[10]

Personal kanban

The application of kanban to personal work originated with Jim Benson[11] after he became exposed to related concepts through his associations with David Anderson,[12][13] Corey Ladas[14] and Don Reinertsen.[15][16][17]

See also

References

  1. ^ Waldner, Jean-Baptiste (September, 1992). Principles of Computer-Integrated Manufacturing [1]. London: John Wiley. pp. 128–132. ISBN 0-471-93450-X. {{cite book}}: Check date values in: |date= (help); External link in |title= (help)
  2. ^ "Kanban". Random House Dictionary. Dictionary.com. 2011. Retrieved April 12, 2011.
  3. ^ Ohno, Taiichi (June 1988). Toyota Production System - beyond large-scale production. Productivity Press. p. 29. ISBN 0-915299-14-3.
  4. ^ Shingō, Shigeo (1989). A Study of the Toyota Production System from an Industrial Engineering Viewpoint. Productivity Press. p. 228. ISBN 0-915299-17-8.
  5. ^ Ohno, Taiichi (June 1988). Toyota Production System - beyond large-scale production. Productivity Press. pp. 25–28. ISBN 0-915299-14-3.
  6. ^ Shingō, Shigeo (1989). A Study of the Toyota Production System from an Industrial Engineering Viewpoint. Productivity Press. p. 30. ISBN 0-915299-17-8.
  7. ^ http://www.microsoft.com/download/en/details.aspx?id=26918
  8. ^ Vernyi, Bruce (December 1, 2005). "Easing into E-Kanban". IndustryWeek. Retrieved April 12, 2008. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  9. ^ Drickhamer, David (2005). "The Kanban E-volution". Material Handling Management: 24–26. {{cite journal}}: Unknown parameter |month= ignored (help)
  10. ^ Cutler, Thomas R. (2006). "Examining Lean Manufacturing Promise". SoftwareMag.com. Retrieved January 29, 2013. {{cite journal}}: Unknown parameter |month= ignored (help)
  11. ^ Benson, Jim (2011). Personal Kanban: Mapping Work - Navigating Life. CreateSpace. ISBN 1-4538-0226-6. {{cite book}}: Unknown parameter |month= ignored (help)
  12. ^ Anderson, David (2003). Agile Management for Software Engineering: Applying the Theory of Constraints for Business Results. Prentice Hall. ISBN 0-13-142460-2. {{cite book}}: Unknown parameter |month= ignored (help)
  13. ^ Anderson, David (2010). Kanban. Blue Hole Press. ISBN 0-9845214-0-2. {{cite book}}: Unknown parameter |month= ignored (help)
  14. ^ Ladas, Corey (2008). Scrumban: Essays on Kanban Systems for Lean Software Development. Modus Cooperandi Press. ISBN 0-578-00214-0. {{cite book}}: Unknown parameter |month= ignored (help)
  15. ^ Reinertsen, Don (1997). Managing the Design Factory. Free Press. ISBN 0-684-83991-1. {{cite book}}: Unknown parameter |month= ignored (help)
  16. ^ Reinertsen, Don (1997). Developing Products in Half the Time: New Rules, New Tools, 2nd Edition. Wiley. ISBN 0-471-29252-4. {{cite book}}: Unknown parameter |month= ignored (help)
  17. ^ Reinertsen, Don (2009). The Principles of Product Development Flow: Second Generation Lean Product Development. Celeritas Publishing. ISBN 1-935401-00-9. {{cite book}}: Unknown parameter |month= ignored (help)

Further reading

  • Waldner, Jean-Baptiste (1992). Principles of Computer-Integrated Manufacturing. John Wiley & Sons. ISBN 0-471-93450-X.
  • Louis, Raymond (2006). Custom Kanban: Designing the System to Meet the Needs of Your Environment. University Park, IL: Productivity Press. ISBN 978-1-56327-345-2.

External links

Look up kanban in Wiktionary, the free dictionary.
Retrieved from "https://en.wikipedia.org/w/index.php?title=Kanban&oldid=535611884"