What is kanban? Meaning, boards, cards and Toyota’s six rules

What kanban means

The Lean Enterprise Institute defines a kanban as “a signaling device that gives authorization and instructions for the production or withdrawal of items” in a pull system. The word is Japanese for “sign” or “signboard”.

The idea comes from the Toyota Production System. Toyota’s own company history records that it introduced a “supermarket method” in 1954: each process collected only the parts it needed from the process before it, the way a shopper takes goods from a shelf that is then restocked. Once a production instruction card was added, the method evolved into the kanban system, the main tool of just-in-time production, which is one of the two pillars of the Toyota Production System.

Today the word is used in two related ways:

• Kanban in production: a card, bin or electronic signal that tells a process what to make or move, and how many, only when the next process has used stock. This stops overproduction, the waste Taiichi Ohno considered the worst.
• Kanban for knowledge work: a visual board where each task is a card that moves through columns such as To do, Doing and Done, with limits on how many tasks can be in progress at once. Software, HR, finance, customer service and BPO teams use it to see bottlenecks and finish work faster.

Both rest on the same principle: work is pulled by real demand, not pushed by a plan or a forecast.

The kanban board

A kanban board makes the flow of work visible. Each column is a stage of the process and each card is one piece of work. The simplest board has three columns:

• To do: work that has been agreed but not started.
• Doing: work in progress (WIP). This column has a limit, for example no more than three cards for a team of three.
• Done: finished work, which shows the team what it has delivered.

The work-in-progress limit is what makes a board a kanban board rather than a to-do list. When the Doing column is full, nobody starts anything new; the team helps finish what is already there. That is the pull: new work enters only when there is capacity for it. A blocked card, shown in a different colour, is a signal to swarm the problem rather than start something else.

Teams add columns that match their real process, for example Backlog, Analyse, Build, Review and Done for a project team, or New ticket, In progress, Waiting for customer and Resolved for a support team. Whiteboards and sticky notes work well for a team in one room; tools such as Jira, Trello, Asana or Microsoft Planner do the same job online.

How to set up a kanban board in five steps

1. Map the current process. Write down the stages work really goes through today, not the ideal. Each stage becomes a column.
2. Put every piece of work on a card. One task, order or request per card, with an owner and a due date where it matters. Use colour for type or priority.
3. Set work-in-progress limits. Start with roughly one card per person in each active column, then adjust. A limit that is never reached is too high.
4. Agree the rules. Decide when a card may move to the next column (what “done” means for each stage) and write it at the top of the column.
5. Review the board daily and improve it monthly. A short stand-up at the board shows what is blocked. Once a month, look at how long cards take to cross the board and remove the biggest delay, using a PDCA cycle.

Individuals can run the same board for their own work. Jim Benson and Tonianne DeMaria Barry called this personal kanban in their 2011 book of the same name, and reduced it to two rules: visualise your work, and limit your work in progress.

Kanban cards in manufacturing: production and withdrawal

On a production line, the kanban travels with the parts. The Lean Enterprise Institute describes two main types:

In a two-card system both cards are used. When the downstream workstation starts a container of parts, its withdrawal card goes back to fetch a replacement container from the upstream stock point. When that container is taken, its production card is removed and placed on the upstream process’s board, which is the only instruction to make more. Nothing is made or moved without a card, so stock between the two processes can never exceed the number of cards in circulation.

Some plants run a single-card system, where one card does the work of both signals. It is simpler, and is usually used where the two processes sit close together and parts can move as soon as they are made. Researchers have documented many other variations, including electronic kanban (e-kanban) signals sent through an ERP system, supplier kanban for purchased parts, and signal kanban for processes that run in batches.

Kanban is one part of a wider flow design. To decide where pull and supermarkets belong in your process, first map the whole flow with value stream mapping, and keep the stock points orderly with 5S.

Toyota’s six rules of kanban

Taiichi Ohno, the Toyota executive who built the system, set out six rules for using kanban in Toyota Production System: Beyond Large-Scale Production (1988). Kanban only works if all six are followed:

1. The later process picks up the number of items shown on the kanban from the earlier process.
2. The earlier process produces items in the quantity and sequence shown on the kanban.
3. No items are made or moved without a kanban.
4. A kanban is always attached to the goods.
5. Defective products are not sent to the next process, so what moves forward is 100% good.
6. Reducing the number of kanbans increases their sensitivity. Fewer cards mean less stock to hide problems, so problems surface and get fixed.

Rules 5 and 6 are the ones most often skipped. Without rule 5, a pull system simply moves defects faster. Without rule 6, kanban becomes a way to manage a fixed level of inventory instead of a way to keep reducing it.

The Kanban Method for office and knowledge work

David J. Anderson adapted kanban for software teams in the 2000s, and the idea spread to other knowledge work. Kanban University now describes the Kanban Method with four principles and six general practices.

The first principle is the practical difference from many other methods: kanban does not ask you to reorganise the team first. You put today’s process on a board and improve it step by step. That makes it a good fit for service operations, such as the BPO and shared services teams that handle a steady flow of tickets and transactions.

What kanban improves

• Less overproduction and inventory: nothing is made before it is needed, so stock and floor space fall.
• Shorter lead time: with less work queued, each item spends less time waiting. Our guide to takt time, cycle time and lead time shows how to measure it.
• Problems become visible: a blocked card or an empty container shows exactly where flow stopped.
• Fewer half-finished tasks: work-in-progress limits reduce switching between tasks.
• Self-managing replenishment: operators and material handlers act on the signal without waiting for a schedule.

Worked example: how many kanban cards do you need?

Once the loop runs smoothly, Toyota’s sixth rule applies: take one card out. If the cell never runs short with four cards, the extra stock was hiding nothing. If it does run short, the shortage points to the real problem, perhaps a long die change on the press, and fixing that is the improvement.

Common mistakes

1. No limit on work in progress.A board without limits is a to-do list on a wall. The limit is what creates pull.
2. Cards on the wall, production still pushed.If the press still runs to a weekly forecast, the cards are decoration. Production must start only when a card arrives.
3. Passing defects forward.Pull with defective parts only speeds up the problem. Fix quality at the source first (Toyota’s fifth rule).
4. Too many columns and too much detail.A board nobody can read in ten seconds stops being used. Keep only the stages that change who works on the item.
5. Never reviewing the numbers.Card counts and limits set on day one should fall over time. If they never change, the system is not improving.

FAQ

Key takeaway

Kanban is not the cards or the board; it is the rule that work starts only when the next step pulls it. Limit work in progress, never pass on defects, and keep reducing the number of cards until problems have nowhere to hide.

Related reading

Sources

1. Lean Enterprise Institute. Kanban (Lean Lexicon). Accessed 11 October 2026.
2. Toyota Motor Corporation. 75 Years of Toyota: modernisation of facilities (the supermarket method and the kanban system). Accessed 11 October 2026.
3. Ohno, T. (1988). Toyota Production System: Beyond Large-Scale Production. Productivity Press.
4. Kanban University. The Kanban Method: principles and general practices. Accessed 11 October 2026.
5. Benson, J., and DeMaria Barry, T. (2011). Personal Kanban: Mapping Work, Navigating Life. Modus Cooperandi Press.
6. Schwaber, K., and Sutherland, J. (2020). The Scrum Guide.
7. Hopp, W. J., and Spearman, M. L. (2004). To pull or not to pull: what is the question? Manufacturing & Service Operations Management, 6(2), 133 to 148.
8. Junior, M. L., and Godinho Filho, M. (2010). Variations of the kanban system: literature review and classification. International Journal of Production Economics, 125(1), 13 to 21.
9. Naufal, A., Jaffar, A., Yusoff, N., and Hayati, N. (2012). Development of kanban system at local manufacturing company in Malaysia: case study. Procedia Engineering, 41, 1721 to 1726.