Kanban

What Kanban is

Kanban is a method for steering ongoing work. Its core is a visible board on which every task sits as a card and moves through columns, for instance from planned through in progress to done. Its second core is the limit: for every column it is fixed how many cards may sit in it at the same time.

The difference from Scrum lies in the rhythm. Kanban has no fixed sections. Work is pulled continuously as soon as space opens in the next column. That is why it suits tasks that arise constantly rather than undertakings with an end.

Why the limit is the real lever

Without a limit, each person works on several things at once, because something is open everywhere. The result is not more speed but less: every task sits half finished for longer, gets forgotten in between and has to be re-read later. Lead time rises although everybody is busy.

With a limit a different effect appears. If a column is full, the person helps with the task it depends on instead of starting a new one. Bottlenecks become visible, because they show up as a queue rather than as activity. That is the actual benefit: the board makes the constraint visible instead of hiding it.

How the board is set up

• Few columns: three to five are enough. Too many columns fragment the flow and make limiting harder.
• A waiting column: tasks waiting for a reply belong visibly separate. Otherwise they look like work.
• Cards of one size: one card, one task. Larger undertakings are split, otherwise they sit in a column for weeks.
• Visible to all: a board only one person sees loses its purpose.

How flow can be measured

Two values show whether the method works. Lead time is the time from taking on to finishing a task. The number of items open at the same time shows how strongly work runs in parallel. When that number falls, lead time usually falls with it, without anyone working faster.

A third value is the share of tasks waiting for a reply. If it is high, the problem is not in the processing but on the other side. Without that split, a waiting problem looks like a performance problem.

Where Kanban fits in online retail

Three areas fit particularly well. Customer service, because new enquiries arrive constantly and handling time shapes the experience. Maintaining product data, because the work is never finished and progress otherwise stays invisible. And the ongoing technical development of a shop, which consists of many small changes.

For a project with a fixed end and dependencies, a plan with dates is better. The strength of Kanban is even flow, not completion within a window.

Frequent questions

• Does it need software? No. A whiteboard or a wall with cards fulfils the purpose entirely.
• How many cards per column? As many as people working on it, times one and a half. Adjust from there.
• What about urgent cases? A column for expedited work with its own small limit. Without a limit everything becomes urgent.