Kanban (“label” or “signboard” in Japanese) is a visual workflow-management method born in Toyota's factories in the 1950s. Its principle: represent each task as a card that moves from column to column on a board, from “To do” through to “Done”, so that work in progress and its blockers are immediately visible to the whole team.
The term covers two complementary uses. In lean manufacturing, the kanban is a replenishment signal in a pull system: you only produce or order what has actually been consumed downstream, which reduces inventory and waste. In project management and agile methods, the kanban board is used to visualise task progress and smooth collaboration.
A key principle is limiting work in progress (WIP, Work In Progress): capping the number of simultaneous tasks per column to avoid spreading too thin, expose bottlenecks and shorten lead times. Kanban differs from planning tools that are more focused on time scheduling, such as the Gantt chart or the critical path method (CPM); it is centred on flow rather than on the schedule.
This column-based visual approach inspires modern task-management tools, and its logic can be found in eyeot's Projects module.