The kanban methodology is a way of managing work by making it visible on a board, limiting how much work is in progress and improving the flow step by step. It starts from the process a team already has, rather than replacing it.
This guide covers the kanban system's roots at Toyota, the Kanban Method used by knowledge-work teams, its principles and six practices, how kanban compares with agile and Scrum, and how to start.
Key takeaways
- Kanban started as a card-based pull system in Toyota's factories.
- In knowledge work, the Kanban Method uses a board, work-in-progress (WIP) limits and flow metrics.
- Kanban starts with what you do now and changes it gradually, with no new roles required.
- Kanban and Scrum are both agile approaches. Kanban uses continuous flow instead of fixed sprints.
- Start with a simple board, add a WIP limit, then measure cycle time and throughput.
What is the kanban methodology?
Kanban is Japanese for signboard or card. The kanban methodology uses visual signals, usually cards on a board, to show each piece of work and its stage. A limit on how much work each stage can hold stops the team from starting more than it can finish.
The result is a pull system: new work starts only when there is capacity for it. Problems such as bottlenecks, blocked items and long waits show up on the board, where the team can deal with them. The kanban method page explains the board itself in detail.
The kanban system at Toyota
The kanban system began at Toyota as part of just in time production. Taiichi Ohno developed it in the late 1940s and 1950s, inspired by the way American supermarkets restocked shelves only as customers took goods.
On the factory floor, a kanban card travels with a container of parts. When a step uses the parts, the card goes back upstream as the signal to make or move more. The number of cards caps the inventory in the loop. The pull system page shows how these loops are sized.
The Kanban Method for knowledge work
In the 2000s, David J. Anderson and others adapted these ideas for software and office teams. His 2010 book Kanban: Successful Evolutionary Change for Your Technology Business set out what is now called the Kanban Method.
Here the cards are tasks, the board shows the team's workflow, and WIP limits replace the fixed number of factory cards. Later work, including Daniel Vacanti's writing on flow and The Kanban Guide, put more weight on flow metrics such as cycle time and throughput.
Kanban principles
The Kanban Method describes a small set of change management principles.
Start with what you do now: map and visualize the current process before changing it.
Agree to pursue improvement through evolutionary change: make small, steady changes rather than a big reorganization.
Encourage acts of leadership at all levels: anyone can spot a problem and suggest a change.
The six kanban practices
Practice 1
Visualize the work
Put every item and every stage on a board, so the whole team sees the same picture.
Practice 2
Limit work in progress
Set a maximum for each stage, and finish work before pulling more.
Practice 3
Manage flow
Watch how items move, and act on blockers and long waits.
Practice 4
Make policies explicit
Write down the rules, such as what done means for each column.
Practice 5
Implement feedback loops
Hold short regular meetings, such as a daily stand-up at the board and a periodic review.
Practice 6
Improve collaboratively, evolve experimentally
Use data and small experiments to change the process.
Kanban vs agile and Scrum
Kanban is one of several agile approaches; it is not an alternative to agile. The common comparison is kanban vs Scrum.
Scrum works in fixed sprints, usually two weeks, with set roles and a planned batch of work per sprint. Kanban has no sprints: work flows continuously, the board limits work in progress, and changes can enter the queue at any time.
Many teams combine them, keeping Scrum's events and adding a kanban board with WIP limits. Kanban often suits work that arrives unpredictably, such as support, operations and maintenance.
Kanban metrics
Cycle time is how long an item takes from start to finish. Throughput is how many items finish per week. WIP is how many items are in progress. Little's Law ties them together: average cycle time equals average WIP divided by average throughput.
A cumulative flow diagram shows all three over time. The Little's Law calculator and the flow metrics tools guide cover how to measure them.
How to start a kanban board
Map the stages your work already goes through, and make a column for each. Start simple: To do, Doing and Done is enough on day one.
Put every current item on the board. Then set a WIP limit on the busiest column, a little below what is in it today, and agree that nobody starts new work while the column is full.
Meet at the board for a few minutes each day, starting from the right-hand column. After a few weeks, look at cycle times and the places work waits, and change one thing. Board tools are compared in the kanban software guide.