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Why Are There So Many Points of View About What Lean Is?

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Dear Gemba Coach,

I’ve been interested in lean for over two years now, and can’t quite understand why after 20 years there are still so many points of view, and no apparent single message under the lean banner. What are your views on this?

That’s an interesting question – I’ve been thinking it over and the answer is both simple and complicated – it’s like asking “why can’t all scientists agree once and for all?” Taiichi Ohno, the chief architect of what we call lean thinking, was explicitly based on the scientific mindset, which has profound implications. But before we get there, let me argue that all lean views do share a number of common values or, more practically, stable preferences:

  • They prefer satisfying customers rather than following the organization’s path of least resistance.
  • They prefer going to the Gemba to see for themselves rather than  reading reports in an office.
  • They prefer seeking to maximize the value-adding part of any work rather than accepting that some waste is the price to pay for doing business.
  • They prefer making work flow smoothly rather than accepting accumulations caused by the optimization of local resources.
  • They prefer pulling work at customer takt time rather than pushing work according to what the central MRP decides is best to optimize machine use.
  • They prefer developing people’s autonomy by teaching them how to master standards rather than ask them to follow procedures and let them find their way by themselves
  • They prefer encouraging individual initiative through step-by-step improvement rather than seek one-time performance jumps through reorganization or modernization investments.
  • They prefer teamwork by teaching every person to solve problems with their colleagues to requiring a show of “team spirit” by “fitting in” and keeping one’s nose clean.
  • They prefer small, flexible equipment to large fast machines.
  • Etc.

My list is by no means exhaustive, and could be expressed in a different way, but I hope that it is demonstrative – these preferences are quite marked and do define the lean field to a large extent. In any work conversations, you can fit people’s positions one way or the other quite easily.

It Depends

When it comes down to specifics, however, I agree, the answer you’ll get from any experienced lean person is most likely “it depends.” Because it does depend. For instance, I was yesterday with a Toyota supplier who was arguing with the Toyota engineers, making the case for a welding process that was cheaper and had many side-advantages, but did create a few occasional defects. The Toyota chaps were adamant that they wanted another welding process that they knew made no defects, but was more expensive and unwieldy. On the one hand, they pushed for their preference for “don’t accept defectives, don’t make defectives, don’t pass on defectives,” and on the other they had to face the practicalities of the situation – I still don’t know how this will play out.

On the other side, I remember another supplier that had put his injection presses in strict flow with assembly, using the press below 50% of its capacity. The Toyota engineers made him change his mind and told him to pull instead, going against the preference for flow – there’s a limit to how much optimization you lose in the name of perfect flow. These two examples highlight that in most practical situations lean thinking really depends of personal evaluations of the situation, and so you’ll get different answers from different people (sometimes different answer from the same person at different times).

Lean thinking is not a religious dogma, it’s scientific thinking applied to business problems, which is why it’s OK in lean that different people have different opinions. Scientific thinking is counter-intuitive. One never learns something new – that works for reading newspapers and chatting with colleagues and friends. Instead, one refine’s one understanding of the world by testing hypotheses and learning to know when they apply, by how much.

As opposed to philosophy, there is no true or false in science – there is likely and unlikely (admittedly, there can be very likely – mostly proven - and very unlikely – mostly disproved). There are no universals but only specific conditions. Similarly, lean thinking’s path to truth is not through learning universal absolutes, but, as Taiichi Ohno framed it, by getting rid of our misconceptions. Most of what we believe is neither right or wrong, it’s right in certain contexts, and wrong in others, and learning is about discovering which is which experimentally. 

Scientific method

Lean thinking

Observe a phenomenon

Plan: Go to the real place, look carefully, measure how a process performs against known standards

Develop a hypothesis to explain this phenomenon

Plan: Apply lean principles, use lean tools, to list the potential factors generating the gap to standard

Formulate a prediction for that hypothesis

Plan: Confirm these factors one-by-one until you can narrow it down to the most likely cause

Test the prediction

Do: implement a countermeasure to the likely cause and

Check: study the countermeasure, measure the effects

Refine the hypothesis

Act: Draw conclusions and refine your understanding of the process

In both approaches, the key is to actively seek where the hypothesis doesn’t fit the facts so well and progressively refine its formulation and the understanding of its conditions (as opposed to try to prove generalities). What makes it work is the commitment to study countermeasure to see how well they work in real life and so to accelerate learning. It’s a tough commitment, and requires real self-discipline. In particular the discipline to realize the first intuitive answer that comes to mind is interesting, but most likely wrong, and it needs to be refined through the PDCA process before becoming meaningful. This discipline essentially distinguishes true lean thinkers from wannabes.

Consequently, every Lean Thinker will have a different response to any given situation. The PDCA process, as with the scientific process, ensures that, through progressive re-statement of hypotheses, people will converge towards areas of confirmed agreement (more likely towards areas of agreement and areas of disagreement, which also mirrors the scientific process). It’s a collective process, just as much as it’s an individual mental effort to commit to it. Over time, you will find topics where there is agreement on a single message (one-piece-flow is about 20% more productive than batching), through repeated experiments by many people, and other subjects where every person holds their own weird notion – that’s OK, it’s precisely how lean thinking is supposed to work. The aim is to develop your deeper thinking, not fill you in with preset conclusions.

Countermeasure to Modern Management

How do we know it works? In companies I know, lean CEOs, like anyone else, work well with some of their directors, and not others. Typically, there will be one or two concrete-head directors who will refuse the Gemba visits from the CEO (one way or other) and will not accept the scientific logic of making hypotheses (causes) explicit, or testing them (countermeasures), but will continue to decide according to reasoning they alone know.

Why aren’t CEOs doing something about it? Well, again, lean is not a religion and you don’t burn people for being heretics – you just try to convince them (until both sides feel that enough is enough, that is). Knowing what is what is often difficult in business, but with an extensive approach to go and see it becomes much clearer: most problems in the company are now opened to the eye, with a few areas of opacity. We can therefore see the size of the mistakes originating from these areas.

I have two specific cases in mind. One, the cost of a commercial director selling projects with high revenue but negative (in one case, very negative) margins. Another, the case of the IT director pushing solutions no one really wants. In both cases, we can actually put a $ value on those avoidable errors – and it ranges in the millions. So the gap to budget is clearly visible because now we understand why in parts of the company where the directors subscribe to lean thinking, and can contrast it with the remaining black holes.

What makes lean unique is that it is the only full-fledged alternative to the “modern management” invented by Alfred Sloan in the previous century. Lean is a full business system with:

  • A lean theory of strategy: Choosing the customers one wants to pursue, accelerate the delivery flow and improve value, sell at market price, and make your margin by better managing costs.
  • A lean HR theory: Customer satisfaction is the key to growth; employee satisfaction is the key to customer satisfaction; fulfilling jobs is the key to employee satisfaction; developing engagement (through kaizen), involvement (through teamwork) and autonomy (through standards) is the key to employee satisfaction.
  • A lean organizational theory: Structure functions around knowledge production and pull value through value stream with a pull system; the management line solves its own problems and improves its own processes.
  • A lean financial theory: Sales growth is a function of built-in-quality; cash growth is a function of reducing lead-time; profitability growth is a function of eliminating waste; capex utilization is a function of better understanding flexibility, autonomation, and technical minimum solutions.
  • A lean supply chain theory: Integrate suppliers by pulling parts and innovations in win-win long-term relationships
  • A lean leadership theory: Develop more leaders by teaching them to put customers first, go and see, ask “why?” and show respect.
  •  A lean managerial theory: Visualize activities; formulate problems; seek root cause; study countermeasures.
  • And so on…

But this entire paradigm is one in which the ultimate aim is not getting you to apply lean rules, but to get you to deliberately practice PDCA in order to deepen your own understanding of your job, business and industry.

Lean is a big tent, to borrow John Shook’s image, and so it should be. To answer directly your question, everyone in lean has their own perspective on lean because they are expressly encouraged to do so: formulating your own hypotheses is par for the course. The clincher is whether you relate your own ideas of lean to those expressed by those who have come before, in order to seek a deeper understanding of lean, or whether you fixate on your personal understanding and dismiss everyone else’s.

Each Lean Thinker is supposed to have his or her own take on lean. But each Lean Thinker is also supposed to constantly amend their views on the basis of the deep lean tradition as well as new evidence. Learning is a collaborative activity between teacher and student. In any paradigm based on learning, the teacher has the responsibility to teach, but the student must take the responsibility to learn. As the old joke goes, how many lean senseis does it take to change a light bulb? The answer is just one, but the light bulb has to really want to change.

5 Comments | Post a Comment
Chet Marchwinski May 5, 2013

(I'm sharing this comment from LEI's Facebook page -Chet, LEI)

Ralf Lippold That is really a more than just good question!!! One deep assumption, and often unspoken reason is the differention of consultants' services!


Kris Hallan May 6, 2013
Great response.

I have always defined lean in the context of a science.  For me, studying lean is like studying physics or studying sociology.  My pet peeve is when people say that they are going to implement lean.  You don't implement lean, you apply and use lean.  You don't ever hear someone say that they are going to "implement physics".  Studying physics is great but when you get into the real world, applying your knowledge of physics is another thing altogether.  Lean is the same way.

There is one thing that does happen in the world of physics and other sciences that might be very helpful however.  After enough consensus and enough testing, sciences develop Laws and Theories.  I think there would be some value from the academic world if some of the "common values" you mentioned were synthesized down to laws.
Michael Balle May 7, 2013
Thanks for a topica? comment. I m currently in Nagoya visiting companies and there is a clear difference between those in Toyota s sphere of influence and others. Are there laws? For that matter are there laws in physics?

I suspect one starting point would be to accept that any idea, or indeed, fact has a "half-life" and is subject to change in time. I m not sure there are laws other than creating techniaues for our mibds to embrace change and improvement rather than seek unchanging absolutes. Great topic for meditation ;^) 
Kris Hallan May 7, 2013

Well yeah, physics does have laws.  The most important three all start with the name Newton.  350 years later and no one disputes them because no one has ever run a valid experiment that violates them (NOTE:  VALID experiment - there are plenty of biased invalid experiments that appear to violate them but they never hold up to peer review).

I just know that there are Laws of Lean.  I know this, in the same way that people knew a ball would bounce back before Newton made statements about equal and opposite reactions, lean gurus know how a factory will perform based upon what they see.  I KNOW that the most efficient process is the one with stable one to one flow.  I think that's a law (stated poorly).  No VALID experiment will ever violate that.

The laws just haven't been codified and verified yet.  I really don't know what it takes in academia for a hypothesis to become a theory and then become a law.  It seems like in todays world of continuous peer review on the internet and the general accuracy of open source systems like wikipedia, that it should be a little faster than in Newton's time (hopefully no one would have to be executed as well...).

Michael Ballé May 12, 2013
Should we be seeking the laws of lean? Interesting theme gor a Gemba Coach column :)
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