Kanban (看板) is pronounced /’kan’ban/ and means ”visual board” – where kan means “visual,” and ban means “card” or “board”. Kanban is a concept developed at and used by Toyota. It is related to lean and just-in-time (JIT) production.
On the surface, there isn’t much difference between an average task board and a kanban board. Each of these boards has various columns that represent the stages that a card needs to go through before it is considered done. The real difference in a kanban board, is not the board itself. The board is just a visual indicator, the same as any task board, and the intention is still to get the cards to the “DONE”-state – that is, delivered to the customer so that they can use the features from that card.
Kanban is not an inventory control system. Rather, it is a scheduling system that tells you what to produce, when to produce it, and how much to produce.
So, what is the purpose of Kanban? In short it tries to:
- Visualize the workflow
Split the work into pieces, write each item on a card and put on the wall.
Use named columns to illustrate where each item is in the workflow. - Limit WIP (Work In Progress) – assign explicit limits to how many items may be in progress at each workflow state.
- Measure the lead time (average time to complete one item, sometimes referred to as “cycle time”), optimize the process to make lead time as small and predictable as possible.
- Create flow focus on the throughput based upon the queuing theory.
- Identify and eliminate bottlenecks - Bottlenecks become clearly visible in real-time. This leads people to collaborate to optimize the whole value chain rather than just their part.
- Pull system features/tasks are pulled through the system instead of being pushed.