Lean teams use kanban to stop overproduction and expose bottlenecks. Limiting work in progress shortens lead time and makes flow problems visible.
Where it comes from
Kanban was developed at Toyota under Taiichi Ohno as part of just-in-time production, inspired by how supermarkets restock shelves. It was later adapted for software and knowledge work.
At a glance
The two-bin kanban loop
Swipe sideways to see the whole diagram.
How to apply Kanban
- 1
Map the workflow
List the real steps work passes through, from request to done. Turn each step into a column or a stocking point.
- 2
Make work visible
Represent every item with a card, bin or ticket. Include blocked and waiting work, not only active tasks.
- 3
Set WIP limits
Cap how many items each step can hold. In production, size the number of kanban cards to demand and replenishment time.
- 4
Pull, don't push
Start new work only when a downstream signal or free capacity calls for it. Finish items before starting more.
- 5
Measure flow
Track lead time, throughput and work in progress. A cumulative flow diagram shows where work piles up.
- 6
Improve continuously
Review the board regularly and adjust limits and policies. Treat recurring blockers as kaizen opportunities.
Worked example
An assembly cell keeps two bins of fasteners at each station. When one bin empties, its card goes to the stockroom and triggers a refill while the second bin is used. Stockouts and overstock both fall, without a central schedule.
Common mistakes
- Building a board without WIP limits, which turns kanban into a to-do list.
- Setting card counts or limits once and never revisiting them as demand changes.
- Hiding blocked or unplanned work off the board, so flow metrics look better than reality.
When Kanban is not the right tool
Kanban suits repeating demand, where the same parts or types of work flow again and again. One-off, highly variable work is harder to run on fixed loops.
It also needs reasonably stable processes. Long breakdowns or changeovers drain the loop, so TPM and SMED often come first.
What is kanban?
Kanban is a pull system that uses visual signals to control how much work enters a process. In Japanese the word means signboard or card. In a factory, a kanban card tells the previous step to make or move only what was just used.
In office and software work, kanban usually means a board of cards with a limit on how much work can be in progress at once. The aim is the same in both cases: start less, finish more, and see where work is stuck.
Anatomy of a kanban board
A kanban board has columns for the stages of the work, such as To do, Doing and Done. Each piece of work is a card that moves from left to right. Each column can carry a work-in-progress (WIP) limit, written at the top.
Many boards add swimlanes for different classes of work, a column split into Doing and Ready for the next step, and a blocked marker on cards that are waiting. When a column reaches its WIP limit, the team finishes work before pulling more.
Kanban board examples
A support team might use Inbox, Triage, In progress, Waiting on customer and Resolved. A maintenance team might use Reported, Planned, Parts ready, In work and Closed. A production cell might use physical cards that circulate between a supermarket and the line.
For a simple template, start with three columns and one WIP limit on the middle column. Add columns only when the team can name a real handoff. Board tools are compared on the kanban software page. For the principles and practices behind the board, read the kanban methodology guide.
Toyota kanban and the Kanban Method
In the Toyota Production System, kanban are signal cards that authorize production or the movement of parts. Taiichi Ohno described the system in his book on TPS.
The Kanban Method for knowledge work, associated with David J. Anderson, adapts the idea to boards and WIP limits. The kanban software and e-kanban categories cover each use.
| Kind | What it signals | Where you see it |
|---|---|---|
| Withdrawal kanban | Move parts from a store to the user | Between a supermarket and a line |
| Production kanban | Make parts to replace what was taken | At the supplying process |
| Signal kanban | Start a batch when stock hits a point | Batch processes such as presses |
| Board kanban | Start new work when WIP allows | Knowledge-work teams |