This paper focuses specifically on kanbans, which are a popular method for implementing pull production control in manufacturing cells. A kanban is a card or some other mechanism that authorizes the workstation to produce a part. When the workstation completes the part, the kanban stays with the part in the downstream workstation’s input queue (or buffer). When the downstream workstation begins working on the part, the kanban is released. In a simple production line, raw material waiting to be processed at the first workstation has no kanbans. At the last station, a part’s kanban is released as soon as the part leaves the station (so that the last station is always authorized to work)