Seth Godin Got "Kanban" Wrong
I don't expect “lean expertise” from marketing blogger Seth Godin (it's nice he often mentions lean concepts), but he got some details about lean wrong and he doesn't allow reader comments on his blog (sort of a one way conversation).
Seth wrote, and I wasn't exactly sure of his point (read his whole post for the context):
In Japanese car factories, this is called kanban. You trade production efficiencies for quality. If a part isn't perfect, the worker refuses to install it. And the entire assembly line stops. Detroit was horrified by this idea. Keeping the assembly line going is the holy grail. Guess what? The line doesn't get stopped very often. Things get better, fast.
Ah… he was already corrected by Ralph Bernstein (from Productivity Press) and Seth added that to his post. It's actually a two-way conversation with Seth if you email him.
Ralph's clarification (which is what I would have said here):
In your posting, In praise of a blank page, your use of the word kanban is incorrect. Kanban refers to a type of visual control that signals an upstream operation to deliver what is needed. (The Wikipedia description to which you linked touches on aspects of the concept, but doesn't get it exactly right.)
What you probably meant was andon.
An andon is a device that calls attention to defects, equipment abnormalities and other problems, or reports the status and needs of a system by means of colored lights. Typically, when a worker on a line encounters a problem, he or she will pull a cord that lights up the andon board and stops the line.
Also, it's a little misleading to say that in such a system, you trade production efficiencies for quality. It's a lot more efficient to stop and eliminate a defect immediately than to repair a finished product (or dozens of finished products) containing the defect. But you are right about one thing: with this kind of system, things do get better fast.
At least Seth's blog believes in “kaizen.” I don't mean to pick on him, I'm not always right myself and I admit that.