The Great A3 Thinking Fallacy

By Jon Miller Updated on May 24th, 2017

What lean or six sigma practitioner doesn’t love A3 thinking? It’s versatile, low-tech, and seemingly easy to learn and teach. The trouble is that just about every plan or report or problem solving summary on a page is getting labeled “A3” nowadays. Most of them aren’t achievable plans, aren’t reporting information effectively and aren’t solving problems at the root cause level in a particularly systematic way. Most of them aren’t on A3 paper, and many are form-filling exercises rather than structured thinking processes. What is the problem with A3 thinking?

The great fallacy is that there is any consensus about such a thing called A3 thinking outside the minds of a handful of people who are or claim to be experts. The origins of the doctrine of A3 thinking come from observations that Toyota does their hoshin planning, problem solving, proposal writing, status reporting, etc. on a single A3 sheet of paper. As books, lean gurus and academics say this is so, this has become doctrine. The content of A3 thinking is nothing new to the world, only the packaging and presentation to a new audience. The lean thought leadership community has been a bit cavalier about selling this approach, or at least has not followed through to make sure that A3 thinking in the wild is performing as intended.

There are two parts to this great fallacy. First, there is the A3. The name causes us to put the emphasis in the wrong place. It tempts us to get the process right by sticking to the form of one A3 or similarly sized sheet of paper. Even the content of an A3 is not so important. Thus the insistence by many lean coaches on using a pencil rather than a pen or printer to fill white space. The underlying thought processes that comes from repeated turning of the PDCA cycle is what makes an A3. I have argued in the past for “A1 thinking” as more appropriate for some types of management processes. Why don’t we call it “One-page PDCA” or something more descriptively accurate? Marketing, mnemonics, first mover advantage, who knows.

This is a classic example of the artifact or tool being mistaken for the behavior that created it, which is to say nothing of the core beliefs that underlie the behavior, almost totally missed on most A3 problem solving documents. Edward T. Hall calls this extension transference in his book Beyond Culture, recommended for those with a deep interest in culture.

Anyone who has paid attention during the first hour of an A3 training class has heard that A3 thinking is nothing about the A3 and all about the thinking. But, what do we even mean by “thinking”? This brings us to the second fallacy of A3 thinking. The word “thinking” in A3 thinking is used as a noun or thing (e.g. I love thinking) not as an adjective or descriptor (e.g. a thinking person). There are three possible definitions we must choose from to understand A3 thinking. They are


  1. The act of having thoughts. This is the general act or process of having notions in our minds. E.g. “He doesn’t like thinking about problems.”
  2. An opinion or judgment. “The thinking of the senior administrators was that the staff were avoiding the problem.”
  3. A method of reasoning. This is a particular way of processing information and sensations in order to arrive at a conclusion, or thought. “Our best leaders were able to draw from a variety of cognitive styles such as critical thinking, visual thinking, strategic thinking, and intuitive thinking.”

Curiously, the so-called “lean thinking” is most likely the second definition, an opinion, judgment, philosophy or belief. While lean is full of methods of thinking, and certainly requires thought, lean thinking as it has been defined around the notions of customer focus, value stream design, pull, flow and the pursuit of perfection is a system of belief, not a method of reasoning.

What we mean by A3 thinking is clearly the third definition, “a method of reasoning”. But this limits the A3 thinking process to only a method of reasoning, and it is necessarily much more. The purpose of the so-called A3 thinking method is to develop the mental capabilities and habits of people within one’s organization, and thereby maintain and improve an adaptive organizational culture. People who are better at reporting progress towards goals succinctly and visually, presenting ideas, problem solving, and decision-making. This in turn leads the opportunity to achieve high performance for longer periods of time.

Looking deeper, A3 thinking is the name of an artifact-behavior found within lean organizations such as Toyota. These include a belief in cultivating humility and open-minded curiosity, making problems visible and aligning people towards serving the customer, following standards, respecting people and engaging everyone in improvement, understanding the purpose of one’s work and the various processes that make up our work, approaching problem solving scientifically and with a sense of urgency, communicating and connecting people in order to build consensus for action, and sharing successful and failed ideas as well as the thinking processes that led to them. Chapter 3 of Creating a Kaizen Culture examines the core values and guiding principles of Toyota, Zappos, Jabil Circuits, Deming and others to arrive at a set of kaizen core beliefs that underpin a lean culture.

The A3 document is a visual countermeasure to irrationality. Most of us don’t even know that we are behaving and thinking irrationally. We think that we are being rational when in fact we are being tricked by our own brains, biases or emotions. The A3 document exposes this first by making it visual, second by putting clear guidelines around what does or does not belong in each step of problem solving (e.g. no causes or solutions in the step 1 problem statement!) and third by forcing us to check both process and results with evidence that the result was not just due to long-term statistical inevitability (chance).

Studies show that our decisions are affected more than we know by our moods, blood sugar levels, and initial impressions of a situation or set of information. The proper use of visual, collaborative, PDCA cycle dialogues (a.k.a. A3 thinking) can helps to counter confirmation bias in the collection of data, recency effect in the scoping of problem solving activity, framing bias, fundamental attribution error and other cognitive biases identified by Daniel Kahnemann and Amos Tversky. We arrive at decisions emotionally, justify rationally. If you suspect that your boss may be making emotional decisions or acting crazy sometimes, you are probably right. While this may not always be a bad thing, neither does it always serve us well when trying to address root cause correction of complex problems, or compete with organizations that are better at rapidly making evidence-based decisions.

On an aside, it would be interesting to know whether anyone who was involved in human resource development at Toyota from the 1970s onward was aware of Kahnemann and Tversky’s work, and incorporated this deliberately, or whether the PDCA / A3 thinking process emerged naturally as a countermeasure to people’s solution-jumping behavior. Based on repeated statements that the Toyota Production System was not designed deliberately as a system, this is possible. It is equally possible that these and other concepts were studied and adapted by Toyota’s operational management researchers.

By all means, we should all keep practicing the PDCA cycle using A3 thinking or whatever useful guard rails are available to us. We need to practice with the awareness that the names we give things affects how we understand them. This in turn affects how we teach this process. If you suspect that you may be shoehorning people into an A3 process in an awkward way, ask.

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  1. Carlos Carrasco

    September 8, 2013 - 4:18 pm

    Paper size does not matter. Key point is use this thinking to deploy lean management from CEO to front line engineers.To sustain PDCA in your company DNA.

  2. eric

    September 9, 2013 - 2:31 am

    This is a great post!
    You give us a history, a refresher on A3-thinking and a discussion on culture all in the same post.
    A prior firm I worked with had great debates on the format for A3’s -totally missing the point and as such never got very far with anything.
    This post has whetted my appetite for the new book!

  3. Bob Emiliani

    September 9, 2013 - 5:31 am

    Hi Jon – I offer a bit of A3 satire in support of your fallacy:
    Problem-solving seen by managers as something for workers to do:
    “A3 management process delegates A3 thinking to workers. Managers stuck on A10 thinking.”
    And, A3 being so good means that more must be better:
    “A3 thinking so successful managers move on to A2 thinking. A1, A0, B0, and C0 thinking are sure to follow.”

  4. Hal Macomber

    September 10, 2013 - 3:14 pm

    Very nice work! I was working with three companies today while they each developed an A3 plan for addressing an initiative for their company. Of everything you addressed in your article, what jumped out today was how right you are when you wrote, “The A3 document is a visual countermeasure to irrationality.” It’s not that we can’t be rational, it’s just that we can’t sustain rationality for extended periods, particularly in groups. The A3 artifact works as a truing mechanism bringing us back to rational deliberations.
    I’ll be directing people to this post.

  5. Eduardo Lander

    September 14, 2013 - 3:19 am

    Hello Jon,
    Although I don’t doubt there are countless misuses of A3s out there, I would like to provide an alternative view.
    A3s in Toyota are ultimately a tool for effective communication. As communication tools, the important thing about them is the story they tell. It must be a coherent story explaining what you want to do and the reasons for it.
    We need to decouple the A3 as a communication tool from all it’s possible uses. When we talk about A3, people normally associate it with a ‘problem solving A3’. But you can do problem solving perfectly well without an A3. The main problem you will have is when you try to explain your thinking to others. You can also use A3s for other non-problem solving applications.
    I’m not trying to diminish the role of the A3. On the contrary. Problem solving without an effective way of communicating about it is almost useless unless you’re operating alone. However, if we recognize A3s as a tool to communicate effectively a coherent and compelling story, it resolves the problems that you mention and opens the possibility to use A3s for many other applications.
    With this in mind, ‘A3 thinking’ should be about communicating effectively… whatever the story is that you want to tell. It’s about condensing your thinking and your facts into a single piece of paper (forcing you to really get down to the essence of the issue at hand) in a way that you can easily and quickly explain it to others. If you use A3s in this way, they will support people development, management, planning, continuous improvement, and all the other activities currently associated with A3s. But they will do it basically by facilitating effective communication.
    If we understand A3s in this way, the size of the paper, and even the structure in it becomes irrelevant. A3s don’t need to follow the same structure every time. In fact, you should adapt them to your needs so they support your thinking process and the story you want to convey. Of course, if you’re using it for problem solving, the best is to use a standard format that everyone will recognize… this will also facilitate communication as the people you will explain the document to know what to expect. But for other applications, we need to use a structure that helps us condense our thinking and facts into an easy to understand story.
    Size is a similar issue. As legend goes, the A3 size was selected since it was the biggest document that could be put into a regular office copier. But the idea is that you put everything into a single document. For example in vehicle development in Toyota during trials, engineers do not have time to create nice A3s. They only have a few days to solve the issue, so they really need to focus on the problem and its causes. However, they still need to communicate effectively to get approval for their proposals, so they take their working documents (pictures, charts, etc.) and attach them to A0 (or bigger) sized foam-core boards. This becomes their ‘A3’ to explain to their management and the chief engineer.
    So, we should start thinking of A3s as a way to condense our thinking so that we can communicate effectively by telling a compelling and logical story. Decouple them from the underlying application and they will become easier and more fun to use, gain wider applicability, and serve their ultimate purpose better.
    Of course… this is only my opinion.

  6. achteck

    September 22, 2013 - 12:21 pm

    An observation on PDCA/A3:
    PDCA as I understand it was derived from Shewhart’s study of C I Lewis’ book. Neither C I Lewis nor Shewhart truly understood the Logical basis given by Josiah Royce. Josiah Royce himself received the knowledge from the original inventor, Charles Sanders Peirce, in a lecture given by Peirce in 1898 at Harvard.
    Josiah Royce received Peirce’s library after he passed away in 1914. Before Royce could properly catalog the enormous library, he passed away in 1916. Consequently C I Lewis and Norbert Wiener (Royce’s grad students) did the best they could with the knowledge in Peirce’s scientific writings.
    It was only through Shewhart’s brilliance and perseverance that he got the essence of PDCA from C I Lewis’ book. Shewhart lacked a background in the concepts of Kata.
    The current World experts in the Scientific Logic of Peirce are the Russians.
    Thank you.
    Very respectfully,

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