The following keywords were used in combination: kanban and
adaptation/adapted, kanban and modification/modified, kanban
and change/changed/altered, kanban and variation, and kanban
and new. Due to its importance, we do not consider, in this paper,
other pull systems like CONWIP and POLCA; only systems that
make direct reference to the kanban are considered. For specific
literature about these systems, see Graves et al. (1995), Gstettner
and Kuhn (1996), Framinan et al. (2003), Riezebos (2009) and Suri
(1998). Also, with respect to hybrid systems, for this review, the
combinations that simply use the kanban system but do not
change any of its properties are not considered as variations.
Some papers that deal with hybrid systems are Deleersnyder et al.
(1992) and Spearman and Zazanis (1992).