Kanban's entire personality is two rules: make the work visible, and stop starting so much. Columns and cards handle the first rule. The work-in-progress limit handles the second, and it's the part people skip, which is why their boards become to-do lists with better graphics.
Three columns: To Do, In Progress, Done. Write every task as a card with a verb in it, small enough to finish in a sitting or two. That's the setup. Resist the urge to start with six columns; each one should earn its place by exposing a real bottleneck, like a Waiting on Review column that always has eleven cards in it.
| Situation | Limit |
|---|---|
| Solo knowledge work | 3 |
| Solo, heavily interrupted | 1–2 |
| Team of N | N + 1 |
| Review column | 2 × reviewers |
The limit on In Progress is what turns the board from a filing system into a workflow. When the column is full and a new task tempts you, the board says no, and you go finish something instead. If the limit never bites, lower it; if it always blocks, you've found your bottleneck, which is the system working.
A free three-column board with drag-and-drop and a WIP limit, saved in your browser.
Open the Kanban Board →Throughput (cards finished per week) tells you if you're shipping. Cycle time (days from start to done) tells you if work flows. If throughput is flat while WIP climbs, you're starting, not finishing, and the fix is a lower limit, not more hours.
Kanban pairs well with time-boxing: work in focus sessions on a pomodoro timer and move the card when the session ends. For multi-week efforts, lift the finished cards into a Gantt chart view when stakeholders ask when things land, and unpack a tangled project with a mind map before its tasks ever become cards.
Kanban is Japanese for signboard or visual card. Toyota borrowed the term in the 1950s for a system where physical cards signaled upstream stations to send more parts, pulling work through the factory only as it was consumed. The board software you use today keeps the name and the pull idea: you pull new work only when you have capacity.
Scrum slices work into fixed-length sprints with planning and retrospection rituals; kanban flows work continuously with limits instead of timeboxes. Scrum asks how much fits in two weeks; kanban asks how much fits in progress right now. Teams mix them freely: sprint cadence for planning, WIP limits for flow.
Very well. The personal version, usually credited to Jim Benson and Tonianne DeMaria Barry's Personal Kanban, is two rules: visualize your work and limit your WIP. A three-column board and a limit of three cards does more for an overflowing to-do list than any productivity system with more rules than that.
Because unfinished work doesn't ship and switching costs are brutal: research on task switching finds each jump between tasks eats measurable minutes of reorientation, and partially done work decays silently (context goes stale, dependencies move). Five things at 20% done deliver nothing; one thing done delivers something. The WIP limit enforces the arithmetic.