Glossary
What is a WIP limit? The cap that makes Kanban work
A WIP limit caps how many items may sit in a column at once. Why it lowers cycle time, and where to apply it.
A WIP limit (work in progress) caps how many cards may sit in a column at once. When the cap is reached nothing new moves in until something moves on. It is the single rule that separates a Kanban board from a colourful to-do list.
Why it works
Too much in parallel costs twice: in switching time and in waiting time. Five items started together all finish later than five done in sequence — for the same amount of work. A limit forces started work to be finished, which lowers cycle time.
Where to apply it
Where work piles up — usually “in progress” and “review”. A usable starting value is about the size of the team, then tighten. If the limit visibly hurts, it is usually right: it is showing you that a handover is stuck somewhere.
In Zuuna
You can set a cap per column; when it is exceeded the column says so visibly instead of quietly allowing it.
FAQ
What do you do when the limit is reached?
Not start the next item, but help finish one that is running. Triggering exactly that behaviour is the point of the limit.
Does a team of two need a WIP limit?
Rarely. The benefit comes from mutual blocking, and with two people that is usually visible anyway.
Is the limit per person or per column?
Per column. A per-person limit optimises individual utilisation — precisely the opposite of the goal.