Sometimes a very powerful manufacturer may instruct suppliers to deliver their parts just-in-time (JIT). In this case, if the manufacturer applied the kanban system to vendors without changing its own production systems, the kanban system would be a demon to the vendors. Although the kanban system is a very e£ective means to realize the JIT concept, it should not be applied to suppliers without corresponding changes in the overall production system of the user company. ™e kanban system is merely a subsystem of the Toyota Production System; the Toyota Production System requires an overall rearrangement of existing production systems.