What’s unique about the Kanban system? (Revisited)

10 years ago, I wrote an article by this title in Karen Wilhelm’s Lean Directions, and a detailed treatment of pull systems in Lean Logistics, pp. 199-270 (2005). While 6 to 10 years in an eternity in Information Technology, it is not in Manufacturing, and I have not seen evidence that technological advances since then have invalidated these discussions yet. Also in 2005, Arun Rao and I wrote a paper on RFID Applications in Manufacturing, which outlined ways this technology could be used, among other things, to implement the Kanban replenishment logic on the side of an assembly line. To the best of our knowledge, it still isn’t broadly used, and bar codes are still the state of the art on the shop floor.

For placing orders with suppliers, on the other hand, the recirculating  hardcopy Kanban has never really taken root in the US, and orders are usually placed electronically. When Kanbans are used with suppliers, they are usually single-use cards printed by the supplier to match electronic orders, that are attached to parts and scanned when the corresponding parts are consumed to trigger a reorder. This is the eKanban system, and more a horseless carriage than a car, in that it is an electronic rendition of a system whose logic was constrained by the use of cards.