Kanban began on the factory floor at Toyota, not in software. In Toyota’s own history of its production system, kanban is described as “a tool that describes which and how many parts are used where and when,” and it is what “made just-in-time production possible.” Each kanban signals the need to replenish a part only in the volume actually consumed downstream.
By pulling parts through the line in exactly the quantities needed, the system lets inventories “within each process” be eliminated, removing the waste of overproduction. Toyota records that the kanban management system was adopted across all of its plants in 1963, as part of the broader Toyota Production System built up under Taiichi Ohno and resting on the twin pillars of just-in-time and jidoka.
Adapted for knowledge work, software kanban keeps the same core ideas: visualize the work, make the flow of work items explicit, and limit the amount of work in progress. A kanban board shows each item moving across columns from “to do” toward “done,” and capping how many items may sit in any stage forces a team to finish work before starting more.
Those work-in-progress limits are what make bottlenecks visible. When a column fills up, the constraint that is slowing the whole system becomes obvious, and the team can address it. Unlike Scrum, kanban prescribes no fixed-length iterations or special roles; it is a method for improving flow that can be layered onto an existing process, which is why it sits comfortably alongside other agile approaches.