The Amazing Adventures of Kanban

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 (

kanban man

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 as signal.png

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.

agile kanban.png

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.

yes we kanban.png

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…

Questions About A3 Problem Solving

By Jon Miller | Post Date: February 25, 2010 12:22 PM on Gemba Panta Rei

These days if you stand next to a Toyota building and listen closely you may hear the sound of many sheets of A3 sized paper being slowly turned into problem solving documents. There are a few big, complex problems that will surely result in improvements, great new processes, and learning for Toyota.

Closer to home, the letter A and the number three can be heard in conversations almost daily in the context of problem solving. It’s a handy shorthand that seems to have stuck. What we hear from time to time in person, on the phone or by e-mail are detailed questions on how A3 problem solving. Here are a few such questions about A3 problems solving we’ve answered for people:

How important is having the right paper size, template or format?

Not very. There is now A4 problem solving at Toyota and each A3/A4 problem solving document should be hand drawn to present the information effectively. Don’t use a single template or it will constrain your thinking.

What is the expectation for taking immediate action on an A3 report to correct a problem or improve an process?

Usually there has been a temporary countermeasure in place long before the A3 in finished, which is due within 24 hours for a quality spill issue. But not all long term countermeasures are implemented automatically.

How are A3 problem solving documents used to build a file for future reference?

They have a “Lessons Learned” database for problem response, engineering and design knowledge and so forth. Having the knowledge base is just half of it, having processes and checks to make sure it is actively used is the important part.

How long does Toyota keep their A3 reports?

Until the next major model change that the problems could be of reference, so max 5 to 6 years.

Is there a time when an A3 should not be used?

Don’t use an A3 if your machine is on fire. If your customer or regulatory agency demands a different reporting format, conform to it. The A3 is the summary of problem solving activity, not the start of it. Go to the actual place, talk to people, see the situation, gather information then work through the PDCA process by writing a good problem statement. If the A3 keeps you from going to gemba, don’t use it.

Questions like these above are evidence that we are asking “What is our process for solving problems and managing through A3 thinking?” We enjoy these questions since they tell us that people are making deeper use of the A3 problem solving process. At the surface level the use of A3 allows people to ask “Have we taken root cause countermeasures?” and “What were the results of countermeasures?” When the Check is done properly, A3s help us ask “What was the process that got us those results?” @ Gemba Panta Rei

The Purpose of Lean

By Jon Miller | Post Date: July 31, 2010 1:07 AM at Gemba Panta Rei

I think the purpose of lean is to get better at choosing good over evil. Most of us understand that lean requires us to choose value over waste, good over bad, and better over good. But to what end? How do we judge what is value and what is waste? The customer defines value, we may say, but many times the customer is fickle, wrong and even wasteful. The history of industrialization and modern business has shown that the pursuit of individual satisfaction or convenience today can lead to collective misery tomorrow. We can’t simply accept bad human judgment as “voice of customer” and blindly put our efforts towards fulfilling those needs efficiently. Genuine lean is essentially continuous improvement paired with respect for humanity. That is a simple yet effective definition of “good”.

I admit that this doesn’t make lean easier to practice. But maybe it makes it more worthwhile.