Generalized kanban Control System (GKCS) was proposed
theoretically by Buzacott (1989) and Zipkin (1989). This system
includes the maintenance of buffers to meet the demand
instantaneously, and the use of signals to authorize the production
and to limit the WIP level. A disadvantage of this system is
the need of a definition and management of two control
parameters per stage, which are the buffer and number of
production order signals. The main differences from the original
kanban is that in the GKCS the demands work separately from the
signals, and even when there are no parts in the workstation
inventory, the signal order is transferred to the precedent stage if
the signal is available. Frein et al. (1995), Karaesmen and Dallery
(2000), Dallery and Liberopoulos (2000), Liberopoulos and Dallery
(2000), and Baynat et al. (2002) give more details about GKCS.