Kanban control (Kanban is Japanese for card) is usually found in the pull systems of just-in-time or Just-in-sequence production setups.
Kanban ensures that information (particularly needs-based Material requirements) is continuously passed back and forth between the stations in a production system. If, for example, an Assembly station needs a certain part and takes that part out of the storage container, its Kanban is sent to the upstream station to request that another of the same part is supplied. The downstream process is the 'customer' of the upstream process.
Originally, Kanban were simply cards that listed the part numbers, quantities, origin, destination and similar such information. Today, these visual Kanban are complemented by container Kanban and storage areas.
Production must be organised according to the one-piece-flow method if Kanban are to be used. Fluctuations in demand are compensated for through levelling (Heijunka).