I decided to repost this since it is such a great way to think about the power of kanbans. It’s from Jon Miller from his blog “gemba panta rei” . Enjoy!
By Jon Miller | Post Date: June 17, 2009 12:57 PM (http://www.gembapantarei.com/2009/06/the_amazing_adventures_of_kanban.html)
Kanban was born nearly 60 years ago. It’s creator, Taiichi Ohno, intended kanban to combat the evil overlord Overproduction, Mother of All Wastes and her Minions of WIP. The battle is far from won. During those six decades kanban has been through some amazing adventures.
Kanban Gains Superpowers
Pokayoke has the power to prevent mistakes. Jiodka frees people to run machines intelligently, rather than be run by them. Heijunka has the power to take choppy demand and smooth it out. Kaizen has the power to make infinite small improvements. All of these players and their many friends bring order and harmony to a production system. Yet one stands above them all: kanban.
Kanban was endowed with three major powers. First is the the power to instruct the production of goods. Within the Toyota Production System and its imitators, only the kanban has the power to cause things to be made. Second is the power to instruct the movement of goods. Like its first power, kanban can cause things to be moved. Third and perhaps most important, kanban can motivate people towards continuous improvement by reducing its own size. Within a kanban system, the less kanban there is, the more improvement is needed. Like a true hero, the power of kanban increases as it diminishes its own presence. Amazing.
Kanban vs. the Communists
From the beginning, the powers of kanban were awesome. Overproduction was stopped in its tracks, Work In Process (WIP) was slashed, and various hidden wastes were exposed and removed through continuous improvement. Almost immediately kanban extended its reach outside of Toyota, the enterprise within which it was born, to its suppliers.
But there was no way that such drastic action would go unnoticed in Japan, the Land of Wa (harmony). A Japanese communist party member accused Toyota of using kanban to make unreasonable demands on suppliers to deliver products right away. Taiichi Ohno was summoned to the Japanese parliament to testify in defense of Toyota’s use of the cards to order suppliers to make deliveries of parts. In the end, the Japanese equivalent of the Fair Trade Commission instructed OEMs to limit the fluctuation of actual monthly orders to suppliers by no more than 10% from the firm monthly orders placed in advance.
Perhaps kanban was becoming too powerful. The government needed step in to curb kanban’s powers, or at least insure they were always used for good. It was a lesson learned. None of the others, not pokayoke, not jidoka, no tkaizen have been called to testify in front of the government, or to face down the communists.
Kanban: the Fickle Hero
But for all its powers kanban was at times fickle. To kanban, jidoka, SMED and pokayoke were just sidekicks, enablers. Kanban treated both 5S and Visual Controls as givens rather than equals. Kaizen may be an equal partner to kanban, but in private kanban lorded over kaizen because of its power to motivate others to improve. While these various players toiled away at making improvements and building systems, kanban expected that their work was all foundation building for the kanban system. Kanban never said a word of thanks, nor asked for one.
Like a temperamental artist who wants just the right type of bottled water and sandwiches in his dressing room, kanban said “I will only work for you if once the workplace is clean and visually organized, quality is reliable, lot sizes are small and a logistics system is in place to support me.” Kanban would not do the heavy lifting for you. Kanban would let you know when you’re failing, but may not always come to the rescue. Kanban is a powerful but fickle hero, relied on at your own risk.
Kanban on the Global Stage
In the 1980s Taiichi Ohno was invited to the USA to speak about the Toyota Production System. Unfortunately the organizers confused kanban, the most noticeable feature of TPS, for the system itself. Kanban stole the show, overshadowing the shadowing even the system it was designed to enable. This was not what its creator Taiichi Ohno intended.
As kanban took the global stage with hubris, inevitably its powers were misunderstood or misdirected. Without the protection of the limits on demand signal fluctuation, OEMs abused suppliers with what can be best described as quasi-kanban. Kanban saw its name sullied by impostors and imitators. Even when kanban was called to use its powers, too often it was pressed into service without the support of its friends pokayoke, SMED, heijunka, visual controls and 5S. Even when they were nearby, they were prevented from working as a team.
Kanban of 1,000 Disguises
Kanban’s powers were weakened as much was lost in translation. In order to effectively combat overproduction in its new and vastly diverging environments, kanban adopted a thousand disguises. Some were more effective than others. Each time kanban answered the call to battle overproduction, it seemed it was in a different form: a lamp, a card, a square on the floor, a box, a cart.
Kanban continues to be misunderstood even today, with many unsure of which is the true face of kanban. But the battles rages on against the evils of overproduction.
Kanban and the Builders of Invisible WIP
Early in the 21st century, kanban found an unexpected band of allies. These people were prolific builders of invisible but deadly WIP. They were software developers. Appearing not as information traveling with the manufactured work product itself but rather represented on a task board, kanban works tirelessly to control even the invisible WIP of lines of code.
Once again, kanban added a new form to its one thousand disguises in order to combat overproduction in on a new battlefield.
Yes We Kanban
Today Kanban finds itself in an uneasy but increasingly important alliance with the Coders through the Limited WIP Society. Flying the banner of kanban’s creator and genius production system designer Taiichi Ohno, kanban has found a common aim with this league of mad scientists: to ultimately defeat WIP and it’s overlord Overproduction.
How much progress will kanban’s alter-ego of Agile Kanban make in exercising its three superpowers across the software development world? Only time will tell.
Kanban Meets Dr. Bahri the Lean Dentist
Kanban may have met its match in Dr. Bahri, the pioneering practitioner of lean dentistry. Dr. Bahri has applied the powers of kanban to instruct the work that dentists and dental hygienists do, to instruct the movement of patients, and to motivate continuous improvement. Wouldn’t it be ironic if six decades into an amazing career, kanban goes for some dental work and finds the power of kanban applied to fixing its teeth?
The villains of overproduction, push and WIP never sleep. The amazing adventures of kanban continue…