The Cybernetics of Ohno’s Production System:

In today’s post, I am looking at the cybernetics of Ohno’s Production System. For this I will start with the ideas of ultrastability from one of the pioneers of Cybernetics, Ross Ashby. It should be noted that I am definitely inspired by Ashby’s ideas and thus may take some liberty with them.

Ashby defined a system as a collection of variables chosen by an observer. “Ultrastability” can be defined as the ability of a system to change its internal organization or structure in response to environmental conditions that threaten to disturb a desired behavior or value of an essential variable (Klaus Krippendorff). Ashby identified that when a system is in a state of stability (equilibrium), and when disturbed by the environment, it is able to get back to the state of equilibrium. This is the feature of an ultrastable system. Let’s look at the example of an organism and its environment. The organism is able to survive or stay viable by making sure that certain variables, such as internal temperature, blood pressure etc. stays in a specific range. Ashby referred to these variables as essential variables. When the essential variables go outside a specific range, the viability of the organism is compromised. Ashby noted:

That an animal should remain ‘alive’, certain variables must remain without certain ‘physiological’ limits. What these variables are, and what the limits, are fixed when the species is fixed. In practice one does not experiment on animals in general, one experiments on one of a particular species. In each species the many physiological variables differ widely in their relevance to survival. Thus, if a man’s hair is shortened from 4 inches to 1 inch, the change is trivial; if his systolic blood pressure drops from 120 mm. of mercury to 30, the change will quickly be fatal.

Ashby noted that the organism affects the environment, and the environment affects the organism: such a system is said to have a feedback. Here the environment does not simply mean the space around the organism. Ashby had a specific definition for environment. Given an organism, its environment is defined as those variables whose changes affect the organism, and those variables which are then changed by the organism’s behavior. It is thus defined in a purely functional, not a material sense. The reactionary part is the sensory-motor framework of the organism. The feedback between the reactionary part (R) of an organism (Orgm) and the environment (Envt.) is depicted below:

Ashby explains this using an example of a kitten resting near a fire. The kitten settles at a safe distance from the fire. If a lump of hot coal falls near the kitten, the environment is threatening to have a direct affect on the essential variables. It the kitten’s brain does nothing; the kitten will get burned. The kitten being the ultrastable system is able to use the correct mechanism – move away from the hot coal and maintain its essential variables in check. Ashby proposed that an ultrastable system has two feedbacks. One feedback that operates frequently while the other feedback that operates infrequently when the essential variables are threatened. The two feedback loops are needed for a system to get back into equilibrium. This is also how the system can learn and adapt. Paul Pangaro and Michael C. Geoghegan note:

What are the minimum conditions of possibility that must exist such that a system can learn and adapt for the better, that is, to increase its chance of survival? Ashby concludes via rigorous argument that the system must have minimally two feedback loops, or double feedback… The first feedback loop, shown on the left side and indicated via up/down arrows, ‘plays its part within each reaction/behavior.’ As Ashby describes, this loop is about the sensory and motor channels between the system and the environment, such as a kitten that adjusts its distance from a fire to maintain warmth but not burn up. The second feedback loop encompasses both the left and right sides of the diagram, and is indicated via long black arrows. Feedback from the environment is shown coming into an icon for a meter in the form of a round dial, signifying that this feedback is measurable insofar as it impinges on the ‘essential variables.’

Ashby depicted his ultrastable system as below:

The first feedback loop can be thought as a mechanism that cannot change itself. It is static, while the second feedback loop is able to operate some parameters so that the structure can change resulting in a new behavior. The second feedback loop acts only when the essential variables are challenged or when the system is not in equilibrium. It must be noted that there are no decisions being made with the first feedback loop. It is simply an action mechanism. It keeps doing what was working before, while the second feedback loop alters the action mechanism to result in a new behavior. If the new behavior is successful in maintaining the essential variables, the new action is continued until it is not effective any longer. When the system is able to counter the threatening situation posed by the environment, it is said to have requisite variety. The law of requisite variety was proposed by Ashby as – only variety can absorb variety. The system must be able to have the requisite variety (in terms of available actions) to counter the variety thrown upon it by the environment. The environment always possesses far more variety than the system. The system must find ways to attenuate the variety coming in, and amplify its own variety to maintain the essential variables.

Let’s look at this with an easy example of a baby. When the baby experiences any sort of discomfort, it starts crying. The crying is the behavior that helps put it back into equilibrium (removal of discomfort) since it gets the attention from its mother or other family members. As the baby grows, its desired variables also get specific (food, water, love, etc.) The action of crying does not always get it what it is looking for. Here the second feedback loop comes in, and it tries a new behavior and see if it results in a better outcome. This behavior could be to point at something or even learning and using words. The new action is kept and used, as long as it becomes successful. The baby/child learns and adapts as needed to meet its own wants and desires.

Pangaro and Geoghegan note that the idea of an ultrastable system is applicable in social realms also. To evoke the social arena, we call the parameters ‘behavior fields.’ When learning by trial-and-error, a behavior field is selected at random by the system, actions are taken by the system that result in observable behaviors, and the consequences of these actions in the environment are in turn registered by the second feedback loop. If the system is approaching the danger zone, and the essential variables begin to go outside their acceptable limits, the step function says, ‘try something else’—repeatedly, if necessary—until the essential variables are stabilized and equilibrium is reached. This new equilibrium is the learned state, the adapted state, and the system locks-in.

It is important to note that the first feedback loop is the overt behavior that is locked in. The system cannot change this unless the second feedback loop is engaged. Stuart Umpleby cites Ashby’s example of an autopilot to explain this further:

In his theory of adaptation two feedback loops are required for a machine to be considered adaptive (Ashby 1960).  The first feedback loop operates frequently and makes small corrections.  The second feedback loop operates infrequently and changes the structure of the system, when the “essential variables” go outside the bounds required for survival.  As an example, Ashby proposed an autopilot.  The usual autopilot simply maintains the stability of an aircraft.  But what if a mechanic miswires the autopilot?  This could cause the plane to crash.  An “ultrastable” autopilot, on the other hand, would detect that essential variables had gone outside their limits and would begin to rewire itself until stability returned, or the plane crashed, depending on which occurred first. The first feedback loop enables an organism or organization to learn a pattern of behavior that is appropriate for a particular environment.  The second feedback loop enables the organism to perceive that the environment has changed and that learning a new pattern of behavior is required.

Ohno’s Production System:

Once I saw that the idea of an ultrastable system may be applied to the social realm, I wanted to see how it can be applied to Ohno’s Production System. Taiichi Ohno is regarded as the father of the famous Toyota Production System. Before it was “Toyota Production System”, it was Ohno’s Production System. Taiichi Ohno was inspired by the challenge issued by Kiichiro Toyoda, the founder of Toyota Motor Corporation. The challenge was to catch up with America in 3 years in order to survive.  Ohno built his ideas with inspirations from Sakichi Toyoda, Kiichiro Toyoda, Henry Ford and the supermarket system. Ohno did a lot of trial and error. And the ideas he implemented, he made sure were followed. Ohno was called “Mr. Mustache”. The operators thought of Ohno as an eccentric. They used to joke that military men used to wear mustaches during World War II, and that it was rare to see a Japanese man with facial hair afterward. “What’s Mustache up to now?” became a common refrain at the plant as Ohno carried out his studies. (Source: Against All Odds, Togo and Wartman)

His ideas were not easily understood by others. He had to tell others that he will take responsibility for the outcomes, in order to convince them to follow his ideas. Ohno could not completely make others understand his vision since his ideas were novel and not always the norm. Ohno was persistent, and he made improvements slowly and steadily. He would later talk about the idea of Toyota being slow and steady like the tortoise. Ohno loved what he did, and he had tremendous passion pushing him forward with his vision. As noted, his ideas were based on trial and error, and were thus perceived as counter-intuitive by others.

Ohno can be viewed as part of the second feedback loop and the assembly line as part of the first feedback loop, while the survivability of the company via the metrics of cost, quality, productivity etc. can be viewed as the “essential variables”. Ohno implemented the ideas of kanban, jidoka etc. on the line, and they were followed. The assembly line could not change the mechanisms established as part of Ohno’s production system. Ohno’s production system can be viewed as a closed system in that the framework is static. Ohno watched how the interactions with the environment went, and how the essential variables were being impacted. Based on this, the existing behaviors were either changed slightly, or changed out all the way until the desired equilibrium was achieved.

Here the production system framework is static because it cannot change itself. The assembly line where it is implemented is closed to changes at a given time. It is “action oriented” without decision powers to make changes to itself. There is no point in copying the framework unless you have the same problems that Ohno faced.

Umpleby also describes the idea of the double feedback loop in terms of quality improvement similar to what we have discussed:

The basic idea of quality improvement is that an organization can be thought of as a collection of processes. The people who work IN each process should also work ON the process, in order to improve it. That is, their day-to-day work involves working IN the process (the first, frequent feedback loop). And about once a week they meet as a quality improvement team to consider suggestions and to design experiments on how to improve the process itself. This is the second, less frequent feedback loop that leads to structural changes in the process. Hence, process improvement methods, which have been so influential in business, are an illustration of Ashby’s theory of adaptation.

This follows the idea of kairyo and kaizen in the Toyota Production System.

Final Words:

It is important to note that Ohno’s Production System is not Toyota Production System is not Toyota’s Production System is not Lean. Ohno’s Production System evolved into Toyota Production System. Toyota’s production system is emergent while Toyota Production System is not. Toyota Production System’s framework can be viewed as a closed system, in the sense that the framework is static. At the same time, the different plants implementing the framework are dynamic due to the simple fact that they exist in an everchanging environment. For an organization to adapt to an everchanging environment, it needs to be ultrastable. An organization can have several ultrastable systems connected with each other resulting in a homeostasis. I will finish with an excellent quote from Mike Jackson.

The organization should have the best possible model of the environment relevant to its purposes… the organization’s structure and information flows should reflect the nature of that environment so that the organization is responsive to it.

Please maintain social distance and wear masks. Stay safe and Always keep on learning…

In case you missed it, my last post was The Cybernetics of a Society:

The Toyota House – Why Jidoka and JIT?

In today’s post, I am looking at the “house” of Toyota Production System. The TPS house is shown above (Source: Toyota Europe website).

The two pillars of the house are Jidoka and Just-In-Time (JIT). I have been thinking about why Jidoka and JIT are the two pillars, and why it is not kanban or kaizen. Jidoka was developed from the ideas of Sakichi Toyoda, father of Kiichiro Toyoda. Kiichiro Toyoda founded the Toyota Motor Corporation. Sakichi Toyoda invented an automatic loom that stopped immediately when the thread broke. He viewed it as automation with human intelligence. Jidoka in Japanese means “automation”, but Toyota’s Jidoka has a human character included in the script such that it still pronounces as “jidoka” but it now means “autonomation”.  The emphasis of Jidoka is quality. We can view Jidoka as not passing defects along or ensuring that the quality of the product is maintained as it flows through the line. The second pillar of the TPS House is JIT. JIT was the brainchild of Kiichiro Toyoda. The idea of JIT is also quite simple – have only what is needed, only in the right quantity, and only when it is needed. Perhaps, one might view that the two pillars of the TPS house are Jidoka and JIT to show respect to the Toyoda elders. I think there is more to this than just showing respect to Sakichi and Kiichiro Toyoda.

One way to explain the two pillars is to view them as two lofty goals –  Jidoka as a call for maximizing quality and JIT for minimizing inventory. I again think there is more to this. Toyota in their 1998 little green & white book explained Jidoka as:

The principle of stopping work immediately when problems occur and preventing the production of defective items is basic to the Toyota Production System. We call that principle Jidoka… we design equipment to detect abnormalities and to stop automatically whenever they occur. And we equip our operators with means of stopping the production flow whenever they note anything suspicious. That mechanical and human jidoka prevents defective items from progressing into subsequent stages of productions, and it prevents the waste that would result from producing a series of defective items… The most fundamental effect of jidoka, though, is the way it changes the nature of line management: it eliminates the need for an operator or operators to watch over each machine continuously – since machines stop automatically when abnormalities occur – and therefore opens the way to major gains in productivity. Jidoka thus is a humanistic approach to configuring the human-machine interface. It liberates operators from the tyranny of the machine and leaves them free to concentrate on tasks that enable them to exercise skill and judgment.

Similarly, they explained JIT as “doing it all for the customer”. They noted:

JIT is making on what is needed, only when it is needed, and only in the amount that is needed. JIT production eliminates lots of kinds of waste. It eliminates the need for maintaining large inventories, which reduces financing costs and storage costs. It eliminates the waste that occurs when changes in specifications or shifts in demand render stocks of old items worthless. It also eliminates the waste that occurs when defects go undetected in the manufacturing of large batches. JIT production, though simple in principle, requires dedication and careful, hard work to implement properly. Once managers and employees have mastered the basic concept, they learn to devise various tools and techniques for putting this concept into practice… (leveled production, pull system, continuous-flow processing and takt time).

The two principles also link to another House of Toyota called the Toyota Way. The two pillars for the Toyota Way are Continuous Improvement and Respect for People. This is explained very well by the architect of the Toyota Way, Fujio Cho:

Toyota is planning and running its production system on the following two basic concepts. First of all, the thing that corresponds to the first recognition of putting forth all efforts to attain low cost production is “reduction of cost through elimination of waste”. This involves making up a system that will thoroughly eliminate waste by assuming that anything other than the minimum amount of equipment, materials, parts, and workers (working time) which are absolutely essential to production are merely surplus that only raises the cost. The thing that corresponds to the second recognition of Japanese diligence, high degree of ability, and favored labor environment is “to make full use of the workers’ capabilities”. In short, treat the workers as human beings and with consideration. Build up a system that will allow the workers to display their full capabilities by themselves.

Toyota Production System is a result of decades of trial and error to find solutions for unique problems faced by Toyota. Toyota did not have luxury to have the state-of-the-art machines or carry large inventory to support the then prevalent mass production system. Taiichi Ohno, the father of TPS, was able to come up with a framework that incorporated the principles of Jidoka and JIT to ensure that Toyota was able to keep the cost low for its customers, increase productivity and yet at the same time provide them high quality products. Jidoka and JIT are aligned very well with the principles of continuous improvement and respect for people. Ohno was famous for asking to do more with less (less people, less inventory etc.). He created conditions where the human capital was nurtured such that they learned to see wastes and came up with ingenious ways to remove them. Ohno created a framework for cultivating capable leaders and for providing employees with necessary practical skills. The idea of Jidoka ensures that quality is not compromised (quality is built-in). The operators can take pride in what they are doing and ensure that it is value-added. The work of the machine is separated from the operator such that they can focus on utilizing their creative skills to remove further waste.

Toyota Production System’s framework can be viewed as a closed system, in the sense that their framework is static. At the same time, the different plants implementing the framework are dynamic due to the simple fact that they exist in an everchanging environment. In a cybernetic sense, information can be processed (meaning can be generated) only in a closed system. And viability requires an open system. Thus, you need to be closed and open at the same time.

The basic concepts of the Toyota Production System are unchanging. But companies implement those concepts differently. One of the great advantages of the Toyota Production System is its adaptability. Yet common threads are apparent in the experience of the companies that have implemented the system successfully. Just-In-Time manufacturing and other elements of the Toyota Production System work best when they are a common basis for synchronizing activity throughout the production sequence. This an egalitarian arrangement in which each process in the production flow becomes the customer for the preceding process and each process becomes a supermarket for the following process.

I will finish with some strong words from Taiichi Ohno:

Those who decide to implement TPS must be fully committed. If you try to adopt only the “good parts” you will fail.

Please maintain social distance and wear masks. Stay safe and Always keep on learning…

In case you missed it, my last post was Whose Gemba Is It Anyway?

Whose Gemba Is It Anyway?

“Gemba” is an important concept in Toyota Production System (TPS) and Lean. Gemba, the Japanese word, can be translated as the actual place. The etymology of Gemba stems to “gen” (meaning “actual”) and “ba” (meaning “place”). One might say that the first lesson in TPS is to go to the gemba. This is often expressed as “genchi genbutsu” or “Go and See to grasp the facts from the source.”

My take on gemba is that it is to do with reality as the word suggests. From here, I will ask the question – whose gemba is it anyway? I am asking this from a post-modernist/Constructivist angle. We are all meaning generating, sensemaking autopoietic creatures. We are organizationally closed, and this means that we generate meaning from the many interactions based on our internal meaning-generating framework. Reality as we perceive it exists in a socially constructed realm and each one of us have our own take of this. There is no objective reality in practice, simply because we do not have direct access to it. Our meaning-generating framework is an emergent property of our brain that has to rely on our sensory organs to make sense of the sensory input coming in. The meaning-generating framework or schemata is ever-evolving and conditioned by our ongoing experiences.

From this standpoint, when we say that we are going to gemba, we need to realize that the gemba as we perceive it is not the same as the gemba perceived by the operator on the floor. Normally, in the manufacturing world, gemba refers to the production floor where the work is taking place. We go there with our preconceived ideas and notions. Thus, the first step is to realize that the gemba as we see it is not what we need to be seeing. The gemba that we need to visit and understand is that of the employee engaged in the actual work. Our role at the gemba is to develop the others and in the process develop ourselves. This circular nature of gemba, understanding and sharing our understanding; developing others and developing ourselves, is very cybernetic in nature. When we try to reflect on our understanding, we are also required to view it from the eyes of the operator who is doing the actual work. Taiichi Ohno, the father of Toyota Production System explained these ideas really well.

Taiichi Ohno described the production floor as a “silent” space that always heightened human awareness and stimulated our imagination. Ohno advised:

When you give an order or an instruction to a subordinate, you have to think as if you were given the order or instructions yourself… You have to struggle together and think about the problem together.

Ohno advises that we should challenge our team members, and in the process challenge ourselves. We should be aware of what we are asking, and in fact we should be able to understand what is doable and what is not doable. If our team member says that the task is impossible, we should be able to counter that. Ohno says:

If you want your subordinate to feel so squeezed that they believe saying “It is impossible” is not an option, you must feel the squeeze and struggle just as hard with it yourself when you give your subordinate the problem.

Here the phrase “feel the squeeze” refers to the challenging process where the employee is pushed to see the problem and come up with a resolution. It is this challenging process that aids in the development of the employee. Ohno wants us to destroy our various preconceptions on a daily basis to further our understanding of gemba. He said:

Another way of stating the essence of the Toyota Production System is to say we are doomed to failure if we do not initiate a daily destruction of our various preconceptions.

Ohno challenged the then prevalent Ford’s Mass Production system with his ideas of a Limited Production system. He offers one more aspect of “whose gemba? thinking”. He noted:

The real waste is making products that don’t sell. Even quality products, if they don’t sell, must be discarded. This waste, in fact, is the most crucial because it is not just a loss to the company – it is a loss to society… The original concept behind Toyota Production System was the total elimination of waste. Carrying this to its logical conclusion, it follows that the function of industry is to accept orders not from an abstract clump known as “the masses,” but from individuals with unique preferences, and to produce similar items accordingly. Waste and high costs occur when we try to produce similar items in large quantities. It is cheaper by far to produce unique items one by one.

Final Words:

Being aware and recognizing that the we are in a social realm and that our perspective of reality is not the only one is of utmost importance. There are multiple perspectives of gemba, and the one that is most important is that of the actual employee most engaged with it. At the same time, we should engage with them in bettering their understanding of their gemba.

I will finish with a very insightful anecdote from the linguist Lera Boroditsky:

Kuuk Thaayore, are an Australian people living primarily in the settlement Pormpuraaw. Boroditsky talks about an experiment that she did with the Kuuk Thaayore. She gave them a set of photographs of her grandfather, ranging from youth to old age, and asked them to order them in the correct sequence. She repeated the test different times. Each time, the sequence of the order was correctly placed, however, the orientation was different. For most of the wester world, we would say that the correct order is from left to right, where the “left side” represents the young age, and as you move towards your right, the subject gets older and older. The Kuuk Thaayore oriented the photographs sometimes left to right, and sometimes top to bottom, and other times diagonally. Boroditsky realized that in their culture, their spacial meaning differs from us. She noted:

“their arrangements were not random: there was a pattern, just a different one from that of English speakers. Instead of arranging time from left to right, they arranged it from east to west. That is, when they were seated facing south, the cards went left to right. When they faced north, the cards went from right to left. When they faced east, the cards came toward the body and so on. This was true even though we never told any of our subjects which direction they faced.”

 If we were to see the orientation, we might say that the Kuuk Thaayore got it wrong. We might say that the correct order is always left to right. It does not matter if we are facing north or east or west, we would always place it left to right. Boroditsky says that perhaps we are so self-centered that we always assume that orientation is based on our self-reference whereas Kuuk Thaayore people are externally-centered that their orientation depends on whether they are facing north or east or west.

The next time you go to gemba, ask yourself “whose gemba is it anyway?”

Please maintain social distance and wear masks. Stay safe and Always keep on learning…

In case you missed it, my last post was Notes on The Good Regulator Theorem:

Weber’s Law at the Gemba:


In today’s post, I am looking at Weber’s Law. Weber’s Law is named after Ernst Heinrich Weber (24 June 1795 – 26 January 1878), a German physician who was one of the pioneers of experimental psychology. I highly recommend the Numberphile YouTube video that explains this in detail.

A simple explanation of Weber’s Law is that we notice things more at a lower intensity than at a higher intensity. For example, the light from your phone in a dark room may appear very bright to you. At the same time, the light from your phone in a bright room may seem insignificant. This type of perception is logarithmic in nature. This means that a change from 1 to 2 feels about the same as a change from 2 to 4, or 4 to 8. The perception of change for an increment of one unit, depends on whether you are experiencing it at a low intensity or a high intensity. At low intensity, a slight change feels stronger.

This is explained in the graph below. The green ovals represent the change of 2 units (2 to 4) and the red ovals represent the same change of 2 units (30 to 32). It can be seen that the perceived intensity is much less for the change from 30 to 32 than for the change from 2 to 4. These are represented by the oval shapes on the Y-axis. To achieve the same level of perceived intensity (change from 2 to 4), we need to create a large amount of intensity (~ change from 30 to 60, a difference of 30 units).


All of this fall under Psychophysics. Per Wikipedia; Psychophysics quantitatively investigates the relationship between physical stimuli and the sensations and perceptions they produce. What does all this have to do with Gemba and Lean?

How often were you able to see problems differently when you came to the production floor as an outsider? Perhaps, you were asked by a friend or colleague for help. You were able to see the problem in a different perspective and you saw something that others missed or you had a better perception of the situation. Most often, we get used to the problems on the floor that we miss seeing things. We do not notice problems until things get almost out of hand or the problems become larger. Small changes in situations do not alert us to problems. This to me is very similar to what Weber’s law teaches us. Small changes in intensity do not appear in our radar unless we are at the low intensity area.

A good example is to imagine a white sheet of paper. If there is one black spot on the paper, it jumps out to us. But if there are many spots on the paper, an additional dot does not jump out to us. It takes a lot of dots before we realize things have changed. One of the experiments that is used to demonstrate Weber’s law is to do with dots. It is easier to see the change from 10 to 20 dots, rather than the change from 110 to 120 dots.


Ohno and Weber’s Law:

Taiichi Ohno was the father of Toyota Production System. I wonder how Taiichi Ohno’s perceptive skills were and whether his skillset followed Weber’s Law. I would like to imagine that his perceptive skillset was linear rather than logarithmic. He trained his perceptive muscles to see a small change no matter what the intensity was. Even if he was used to his gemba, he was able to see waste no matter if it was small, medium or large. Ohno is famous for his Ohno circle, which was a chalk circle he drew on the production floor for his supervisors, engineers etc. He would have them stand in the circle to observe an operation, trying to see waste in the operation. Waste is anything that has no value. Ohno was an expert who could differentiate a little amount of waste. Ohno’s Weber’s Law plot might appear to be linear instead of being logarithmic, when compared to a student like me.

Weber Ohno

What we can learn from Weber’s Law is that we need to improve our perception skills to perceive waste as it happens. We should not get used to “waste”. When there is already so much waste, the ability to perceive it is further diminished. It would take a larger event to make us notice of problems on the floor. We lack the ability to perceive waste accurately. We can only understand it based on what has been perceived already. This would mean that we should go to gemba more often, and each time try to see things with a fresh set of eyes. As the Toyota saying goes, we should think with our hands and see with our feet. Change spots from where you are observing a process. Understand that gemba not only means the actual place, but it also includes people, equipment, parts and the environment. We should avoid going with preconceived notions and biases. As we construct our understanding try to include input from the actual users/operators as much as possible. Learn to see differently.

Final Words:

One of the examples I came up with for this post is about cleaning rooms. Have you noticed that cleaner rooms get messy fast? Actually, we perceive a slight increase in messiness when the room is clean versus when it is not. The already messy room requires a larger amount of mess to have a noticeable difference. What Weber’s law shows us is that our natural instinct is not to think linearly.

Humans evolved to notice and minimize relative error. As noted on an article on the Science20 website:

One of the researchers’ assumptions is that if you were designing a nervous system for humans living in the ancestral environment, with the aim that it accurately represents the world around them, the right type of error to minimize would be relative error, not absolute error. After all, being off by four matters much more if the question is whether there are one or five hungry lions in the tall grass around you than if the question is whether there are 96 or 100 antelope in the herd you’ve just spotted.

The STIR researchers demonstrated that if you’re trying to minimize relative error, using a logarithmic scale is the best approach under two different conditions: One is if you’re trying to store your representations of the outside world in memory; the other is if sensory stimuli in the outside world happen to fall into particular statistical patterns.

Perhaps, all this means that we learn to see waste and solve problems on a logarithmic scale. And as we get better, we should train to see and solve problems on a linear scale. Any small amount of waste is waste that can be eliminated and the operation to be improved. It does not matter where you are on the X-axis of the Weber’s law plot. I will finish with an excellent anecdote from one of my heroes, Heinz von Foerster, who was also a nephew of Ludwig Wittgenstein. I have slightly paraphrased the anecdote.

Let me illustrate this point. I don’t know whether you remember Castaneda and his teacher, Don Juan. Castaneda wants to learn about things that go on in the immense expanses of the Mexican chaparral. Don Juan says, “You see this … ?” and Castaneda says “What? I don’t see anything.” Next time, Don Juan says, “Look here!” Castaneda looks, and says, “I don’t see a thing.” Don Juan gets desperate, because he wants really to teach him how to see. Finally, Don Juan has a solution. “I see now what your problem is. You can only see things that you can explain. Forget about explanations, and you will see.”

You become surprised because you abandoned your preoccupation with explanations. Therefore, you are able to see. I hope you will continue to be surprised.

In case you missed it, my last post was OODA Loop at the Gemba:

I also encourage the readers to check out my other similar posts:

Drawing at the Gemba

The Colors of Waste

Maurice Merleau-Ponty’s Lean Lessons

The Illegitimate Sensei:


In today’s post, I am writing about coaching. My inspiration is Heinz von Foerster, the giant in Cybernetics. Von Foerster was the nephew of another giant in philosophy, Ludwig Wittgenstein.

Heinz von Foerster defined an illegitimate question to be one for which the answer is known. A legitimate question is one for which the answer is not known.

Von Foerster dreamt of a society where there was an educational system that promoted asking legitimate questions. The idea of an “illegitimate question” is a fascinating one. Von Foerster’s point was that our education system teaches kids to learn answers to questions that they expect to be asked in a test. This is rote learning and does not make them think. Along these lines, I thought about senseis in Lean. Sensei is a Japanese word that literally means “person who came before you” or elder. The word has come to mean “teacher” especially in martial arts. In Toyota Production System, the original Lean, much emphasis is placed on developing people. One of Toyota’s slogan was “Good Thinking, Good Products.” Another slogan used by Toyota is “Monozukuri wa hitozukuri” or “making things is about making (developing) people.” Additionally, one of two pillars of the Toyota Way is “Respect for People.” In this light, one can see that a Lean sensei’s primary focus is on developing his/her disciple.

A sensei should take care to not just impart his wisdom by giving answers to problems. The sensei should probe the disciple’s current knowledge and guide him towards learning. All managers are senseis in many regards. They are tasked with developing his or her team members. Generally, the manager’s first instinct is to tell people what to do. When you think on this further, you can see that here the emphasis is on the manager getting his or her job done. This means that the employee is replaceable. You could bring in another employee and expect the job to be done. This is mechanistic thinking at best. The manager is viewing the employee as a machine that can get the job done. The employee will learn the task to be done this way. However, the employee does not get developed to think. The employee becomes an accessory to the manager to get the job done. This does not improve the quality of life for the employee. Telling an employee what to do is a reductionist approach, while training them to think and come up with ways to solve the problems is a holistic approach.

Suzumura Style and Cho-san Style:

Bob Emiliani [1] talks about the Suzumura style and Cho-san style of coaching for kaizen. Suzumura was one of Taiichi Ohno’s disciples and was famous for being short-tempered, strict, and sometimes demeaning. This is one of the stereotypes of Japanese Lean senseis. In fact, Emiliani called it the “Scary style”. On the other hand, is Fujio Cho, Toyota’s ex-President, who was well known for his gentle, caring nature on the floor. Cho was also a close disciple of Ohno. Cho is famous for his lesson of “Go See, Ask Why, and Show Respect.” Ohno talked about scolding supervisors at the gemba. [2] He said:

When I scold the supervisors on the gemba, the workers see that their boss is getting yelled at and they sympathize with their boss. Then it becomes easier for the supervisor to correct the workers. If you call the supervisor away to a dark corner somewhere to scold them, the message does not get through… When the workers see their boss getting scolded and they think it is because they are not doing something right, then the next time the supervisor corrects them, they will listen.

This is an interesting approach by Ohno! In either case, the employees are not being spoon fed the solution. The sensei is trying to challenge the supervisor to see the waste, and make improvements. The sensei gives the demand and the autonomy to the supervisor to get to the challenge. This way, the supervisor learns what needs to be done and becomes creative. Finally, the more problems that are solved, the better the supervisor gets at finding and solving problems. Additionally, they are now at a position to develop his or her subordinates.

Double Loop Learning:

The idea of Chris Argyris’ [3] Double Loop learning also falls nicely into place here. Telling an employee what to do may train the employee to do that task well. This is similar to single loop learning, where doing a task again and again helps with doing that task better the next time. Coaching the employee to find solutions on their own is similar to double loop learning. The employee gets to understand the “why” behind the problem, and modify his/her mental model and thinking to come up with creative ways to solve the problem. This type of learning improves the employee’s ability to solve a new problem in the future. Solving today’s problem gives the employee the experience and wisdom to solve a completely different and new problem in the future. Argyris wrote:

Organizational learning is a process of detecting and correcting error. Error is for our purposes any feature of knowledge or knowing that inhibits learning. When the process enables the organization to carry on its present policies or achieve its objectives, the process may be called single loop learning. Single loop learning can be compared with a thermostat that learns when it is too hot or too cold and then turns the heat on or off. The thermostat is able to perform this task because it can receive information (the temperature of the room) and therefore take corrective action. If the thermostat could question itself about whether it should be set at 68 degrees, it would be capable not only of detecting error but of questioning the underlying policies and goals as well as its own program. That is a second and more comprehensive inquiry; hence it might be called double loop learning.

Final Words:

Heinz von Foerster had a way with words and was a very wise man. I will finish with his lesson on legitimate questions. [4]

Tests are devices to establish a measure of trivialization. A perfect score in a test is indicative of perfect trivialization: the student is completely predictable and thus can be admitted into society. He will cause neither any surprises nor any trouble. I shall call a question to which the answer is known an “illegitimate question.” Wouldn’t it be fascinating to contemplate an educational system that would ask of its students to answer “legitimate questions” that is questions to which the answers are unknown. (H. Br ̈un in a personal communication) Would it not be even more fascinating to conceive of a society that would establish such an educational system?

The necessary condition for such an utopia is that its members perceive one another as autonomous, non-trivial beings. Such a society shall make, I predict, some of the most astounding discoveries. Just for the record, I shall list the following three:

  1. “Education is neither a right nor a privilege: it is a necessity.”
  2. “Education is learning to ask legitimate questions.”

A society who has made these two discoveries will ultimately be able to discover the third and most utopian one:

  1. “A is better off when B is better off.”

Von Foerster called the third idea a moral imperative.

Always keep on learning…

In case you missed it, my last post was Book Review – Seeing To Understand:

[1] Better Thinking, Better Results – Bob Emiliani

[2] Workplace Management – Taiichi Ohno

[3] Double Loop Learning in Organizations – Chris Argyris, September 1977 Harvard Business Review Issue

[4] Perception of the Future and the Future of Perception – Heinz von Foerster

Ohno and VUT:

Ohno and Kingsman

One of my favorite “Factory Physics [1] equations” is Kingman’s equation, usually represented as “VUT”. The VUT equation is named after Sir John Kingman, a British mathematician.

The equation is as follows:


The first factor represents variability and is a combination of variability factors representing arrival and service times (flow variability and process variability). The second factor represents utilization of the work station or the assembly line. The third factor represents the average processing time in the work station or the assembly line. The VUT equation shows that the average cycle time or wait time is proportional to the product of variability, utilization and process time.

The most important lesson from VUT is:

If a station increase utilization without making any other change, average WIP (work in process) and cycle time will increase in a highly nonlinear fashion.

The influence of variability on cycle time is shown below. The red line shows that with high variability, any increase in utilization will results in an exponentially higher cycle time. If the variability is low (indicated by the green line), then the increase in the cycle time happens at a slower rate. If there was no variability, then the cycle time will be a constant. In other words, an increase in variability always degrades the performance of a production system.

VUT chart

Some of the lessons that we can learn from VUT equation are:

  1. To maintain a steady cycle time, reduce utilization if variability cannot be reduced. Reducing utilization means increasing capacity. As demand goes up, do not try to run the line at 100% utilization.
  2. The VUT equation can be used in conjunction with Little’s Law. Little’s Law states that WIP is proportional to the product of Throughput rate and Cycle Time. In other words, WIP is proportional to the product of Throughput and VUT. If you try to reduce WIP without trying to reduce variability, the throughput will go down. Thus, implementing one-piece flow without trying to reduce variability will result in a reduction in throughput.
  3. Reducing process variability will reduce cycle time variability.
  4. Adding buffer space at bottlenecks will improve throughput. Adding buffers at non-bottlenecks will not have a positive impact on throughput.
  5. Variability shall always be buffered either in the form of inventory, capacity or time. If variability is not reduced, you pay in terms of high WIP, underutilized capacity and reduced customer service. This is further explained here.
  6. Utilization effects are not linear but are highly nonlinear. Thus, the effect of variability at 40% utilization is not half of the effect of variability at 80% utilization.
  7. Reducing variability reduces uncertainty regarding cycle time or project lead times.
  8. First reduce variability and then go for increasing throughput.
  9. The rule of thumb is to run a line at or near 80% utilization. You should experiment yourself to learn more about your production system.
  10. In Lean, the variability factor can viewed as Mura (unevenness) and the burden from pushing for 100% utilization can be viewed as Muri (overburdening). Both result in Muda (waste).

VUT and TPS(Lean):

Taiichi Ohno, the father of Toyota Production System (TPS), learned by trial and error and by actively learning from the gemba. Ohno realized early on that the first step in increasing throughput is by achieving stability. The idea of variability is closely tied to the idea of Mura (unevenness) in TPS. Ohno pushed for the idea of standard work for kaizen. He taught that kaizen is not possible without standard work. Standard work is aimed at reduction of variability in the process. In addition, Ohno came up with kanban to minimize variability in the process flow. He further pushed for reduction in WIP once process stability was achieved. Ohno constantly pushed to remove “waste” from the production system through kaizen. This continuous improvement cycle helped to maintain process stability. As Art Smalley puts it, What Toyota (Ohno) learned the hard way is that in the beginning of a transformation you need lots of basic stability before you can succeed with the more sophisticated elements of lean… Veterans of Toyota comment that certain pre-conditions are needed for a lean implementation to proceed smoothly.  These include relatively few problems in equipment uptime, available materials with few defects, and strong supervision at the production line level.[2]

Art Smalley further gives four questions to evaluate stability:

  1. Do you have enough machine uptime to produce customer demand?
  2. Do you have enough material on hand every day to meet your production needs?
  3. Do you have enough trained employees available to handle the current processes?
  4. Do you have work methods, such as basic work instructions, defined or standards in place?

If the answer is emphatically “no” to any of these questions, stop and fix the problem before proceeding. Attempting to flow product exactly to customer demand with untrained employees, poor supervision, or little inventory in place is a recipe for disaster.

It is said that Ohno first go-to method to train the production team to start thinking in terms of improvement is to ask the line to maintain current throughput with one less operator. In many regards, this can be viewed as reducing capacity or increasing utilization. As we learned from VUT, increasing utilization is a bad thing. Why would Ohno do that?

Ohno firmly believed that doing is the main way to learn something. Ohno advises that – “Knowledge is something you buy with the money. Wisdom is something you acquire by doing it.” Ohno was able to “see” wastes in the process that hindered the flow. Ohno had to train others to see the wastes like he did. It is likely that Ohno was able to the see the wastes in the current process that the leads or the operators are not able to see. This could be because they are able to meet the demand with their current process. The only way that Ohno could make them improve further was by asking them to do the same with one less operator. The removal of one operator challenged the team to look at their standard work, and the process to see where excess waste was. This idea of challenge is part of the “respect for people” pillar of the Toyota Way. It is said that TPS also stands for “Thinking Production System”, a system that makes people think! Toyota develops their people to think and be autonomous to see problems and fix them. Fujio Cho, ex-President of Toyota Motor Corporation and a student of Ohno, has said that the Toyota Production System pioneered by Ohno is not just a method of production; it is a different way of looking and thinking about things. Ohno developed the management team by giving genchi genbutsu-based practical tasks through which the team members were matched in a “competition of wits” against him [3]. Cho called it the hands-on human resources “nurturing” that Ohno promoted. Ohno believed that if he was in a position to give orders, he could not do that unless he has had a lot of confidence about what he was asking. Ohno saw that the current condition can be improved, and he challenged the team to do that by knowingly pushing the utilization up.

I welcome to reader to learn more about VUT here and here.

Always keep on learning…

In case you missed it, my last post was The Cybernetic View of Quality Control:

[1] Factory Physics by Wallace Hopp and Mark Spearman

[2] Basic Stability is Basic to Lean Manufacturing Success by Art Smalley

[3] Workplace Management by Taiichi Ohno

Maurice Merleau-Ponty’s Lean Lessons:


In today’s post, I am writing about three great Lean lessons inspired by the late French philosopher, Maurice Merleau-Ponty. Merleau-Ponty was a phenomenologist who believed that our conceptual framework is inherently flawed. He wanted to develop a framework that accurately reflected the nature of things it described. His insight was that we perceive things by interacting with them. The more we interact, the deeper our perception becomes, and the more we can enjoy the richness of the object we are interacting with. Merleau-Ponty believed that being in the world is the embodied experience of perception. The world does not present itself “all at once” to the perceiver. The perceiver has to go through an ongoing process of exploration and discovery and a deeper understanding emerges gradually through this ongoing process.

The three lessons I have chosen are interrelated and are about perception. Lean teaches us the importance of Genchi Genbutsu or Go to See and Grasp the Situation. The following three ideas align really well with the idea of Genchi Genbutsu.

  • The philosopher is a perpetual beginner…

Merleau-Ponty’s point here is that a true philosopher does not take things for granted. I will replace the word “philosopher” with “Lean leader”. Thus, the Lean leader is a perpetual beginner. As Lean leaders, we are ready to learn everyday from the gemba. We are continually improving our perception from the gemba. We must resist the urge to feel that we have completed our learning and that there is nothing left to learn. To paraphrase Merleau-Ponty, we need to learn to see the world (and gemba) as something new every single day. We must start to “see” with a beginner’s mind to learn.


  • In order to see the world, we must break with our familiar acceptance of it:

Our ability to observe depends on our preconceived notions and biases. Understanding of a phenomenon lies under the surface in the nuances and the contradictions. Our familiarity based on our prior biases cloud our ability to “see”, and Merleau-Ponty advises us to break our familiar acceptance in order to see the world. We must put aside our assumptions and relearn to see the world with fresh eyes.


  • Nothing is more difficult than to know precisely what we see:

This idea to me is simply wonderful. When we are at the Gemba to see or observe, we jump to conclusions. We believe that we “see” the problem and know how to fix it. The act of observing and perceiving requires a vantage point. This vantage point comes with prejudices. We believe that what we see is quite simple and straightforward, and that we have a clear perspective. This actually hinders our ability to know and understand the phenomenon we are perceiving. From a philosophy standpoint, we believe that what we perceive is reality. This of course is incomplete and most of the time a faulty notion.

Final Words:

The three ideas of Merleau-Ponty advises us to go to the Gemba more and interact with it to improve our understanding. We should look at the real workplace with the eyes of a beginner, and keep interacting with an open mind without preconceived notions to learn. We should resist the urge to believe that we know precisely what we see.

Taiichi Ohno was famous for his Ohno circles. Taiichi Ohno drew chalk circles and made the supervisor or the engineer stand in the circle to observe an operation until he was able to “see” the waste that Ohno saw. Similar to Merleau-Ponty, Ohno also advises us to go and see without preconceived notions. Go and see a lot. This helps us to improve our perception. The more we do it, the better we get at it. And yet, we should strive to remain a perpetual beginner.

Always keep on learning…

In case you missed it, my last post was Toyota Physics:

Toyota Physics:


In today’s post, I am looking at Factory Physics and Toyota Production System. My main references for the post are the 1977 paper coauthored by ex-Toyota president Fujio Cho [1] and key ideas from Factory Physics [2].

One of my favorite definitions of “Lean” comes from Wallace J. Hopp and Mark L. Spearman (Factory Physics). They defined Lean as:

Lean is fundamentally about minimizing the cost of buffering variability… Production of goods or services is lean if it is accomplished with minimal buffering costs.

Variability is the norm of life. Variability is all around us. Variability impacts the 6Ms of production – Man, Method, Machine, Material, Mother Nature (Environment) and Measurement. Variability degrades the performance of a system. Variability is anything that causes the system to depart from regular, predictable behavior. Variability can be internal in the form of quality issues, operator unavailability, material shortage, skill levels, equipment issues etc. Variability can also be external in the form of irregular flow of customer orders, requests for diverse products, supplier issues, new regulations etc.

Factory Physics teaches us that any system has three buffers to deal with variability – Inventory, Capacity and Time.

Regardless of its source, all variability in a production system will be buffered. A fundamental principle of factory physics is that there are three types of variability buffer: inventory, capacity, and time.

For example, safety stocks represent inventory buffers against variability in demand and/or production. Excess capacity can also provide protection (i.e., a capacity buffer) against fluctuations in demand and/or production. Finally, safety lead times provide a time buffer against production variability. While the exact mix of buffers is a management decision, the decision of whether or not to buffer variability is not. If variability exists, it will be buffered somehow.

A Capacity buffer in the form of overtime is quite familiar to any organization. If there is excess demand, use overtime to get out of the backorder situation. The Inventory buffer in the form of just-in-case or safety stocks is also easy to understand. The last form, time buffer, is unfortunately suffered by the customer. When an organization cannot produce products on time, the lead time goes up and the customer has to wait. The time buffer is automatically enforced by the system when the other two buffers are not used wisely.

Another way to look at these buffers is to see what is waiting to know what buffer is available to use:

                Inventory buffer – parts are waiting

                Capacity buffer – resources (labor, equipment etc.) are waiting

                Time buffer – customers are waiting.

A successful organization is able to swap the right buffer at the right time in the right amount. The success of Taiichi Ohno and Toyota was in developing a production system framework through decades of trial and error that excelled in minimizing the cost of buffering variability.

Toyota could not match Ford or any other competitor in carrying the inventory required by the mass production system. Toyota focused first on the capacity buffer. They modified equipment to match what they needed. They created the Just-in-Time system so that required product is made at the right time and in the right quantity. They also had operators manage more than one piece of equipment at a time. Toyota was also able to bring down the set-up times for their equipment which allowed them to run a variety of parts in smaller lots. They focused on the flow of parts and redid the factory layout to match the process flow. With the development of the kanban system, Ohno was able to create a full-fledged pull system to support the Just-in-Time concept. As Hopp and Spearman point out, Toyota utilized the capacity buffer wisely. [3]

At a time when automotive plants generally ran three shifts a day, Toyota went to a two-shift schedule, with 10-hour shifts separated by 2-hour preventive maintenance (PM) periods. These PM periods served as capacity buffers to allow shifts to make up any shortfalls on their production quotas. With these capacity buffers as backup, Toyota could afford to run much leaner with respect to inventory.

A key part of increasing capacity was also where Toyota shined, with the concept of Respect for Humanity. This is very well described in the 1977 paper – Toyota production system and Kanban system Materialization of just-in-time and respect-for-human system (Y. Sugimori, K. Kusunoki, F. Cho & S. Uchikawa). The authors document that Toyota recognized the need for producing better quality goods having higher added value and at an even lower production cost than those of the other countries. Toyota focused on a system that would allow the workers to display their full capabilities by themselves. The authors detailed the “requirements” that existed at the time for the automotive industry – the need to carry large inventory of many different components.

The ordinary production control system in such an industry consists of fulfilling the production schedules by holding work-in-process inventory over all processes as a means of absorbing troubles in the processes and changes in demand. However, such a system in practice often creates excessive unbalance of stock between the processes, which often leads to dead stock. On the other hand, it can easily fall into the condition of having excessive equipment and surplus of workers, which is not conformable to Toyota’s recognition.

This section in the paper identifies the inventory buffer and capacity buffer quite well. Toyota was not keen on carrying inventory and having extra equipment and surplus of labor since that would increase the cost of production. Ohno realized that focusing on value added work would allow them to utilize the capacity buffer efficiently.

In order to improve their capacity buffer, Toyota focused on Respect for Humanity. The paper states:

The just-in-time production is a method whereby the production lead time is greatly shortened by maintaining the conformity to changes by having ” all processes produce the necessary parts at the necessary time and have on hand only the minimum stock necessary to hold the processes together”. In addition, by checking the degree of inventory quantity and production lead time as policy variables, this production method discloses existence of surplus equipment and workers. This is the starting point to the second characteristic of Toyota Production System (the first being Just-In-Time production), that is, to make full use of the workers’ capability.

Toyota clearly identified that they were not going to utilize the inventory buffer or the time buffer in the form of production lead time.

Toyota has succeeded in reducing the lot size through greatly shortening the· setup time, improving production methods including the elimination of in-process inventory within the process resulting from ordering of multipurpose machining equipment in accordance with the processing requirements for a product line, and improving conveyance resulting from repetitive mixed loading.

In fact, Toyota specifically called out not using the inventory buffer.

In the conventional production control system, existence of inventory is appreciated as a means to absorb troubles and fluctuations in demand and to smooth fluctuations in load of processes. In contrast to this, Toyota sees the stock on hand as being only a collection of troubles and bad causes.

Toyota went on to clearly state that carrying an inventory buffer goes against their need for respect for humanity.

Such latency of waste makes it difficult for workers to display their capability and it even becomes obstructive of an ever-lasting evolution of a company.

The paper also goes into detail on the formulation of number of the kanbans needed. They identify that the capacity buffer in the form of overtime and inventory buffer can be used initially while the plant focuses on making improvements.

Toyota defined themselves as an organization where conditions are enforced to make the necessity for improvement immediately visible. This is in a sense a pull system for improvements.

Any employee at Toyota has a right to make an improvement on the waste he has found. In the just-in-time production, all processes and all shops are kept in the state where they have no surplus so that if trouble is left, unattended, the line will immediately stop running and will affect the entire plant. The necessity for improvement can be easily understood by anyone. Therefore, Toyota is endeavouring to make up a working place where not only the managers and foremen but also all workers can detect trouble. This is called ‘ visible control ‘. Through visible control, all workers are taking positive steps to improve a lot of waste they have found. And the authority and responsibility for running and improving the workshop have been delegated to the workers themselves, which is the most distinctive feature of Toyota’s respect for human system.

Always keep on learning…

In case you missed it, my last post was My recent tweets…

[1] Y. SUGIMORI , K. KUSUNOKI , F. CHO & S. UCHIKAWA (1977) Toyota production system and Kanban system Materialization of just-in-time and respect-for-human system, THE INTERNATIONAL JOURNAL OF PRODUCTION RESEARCH, 15:6, 553-564, DOI:10.1080/00207547708943149

[2] Factory Physics, 3rd edition

[3] Wallace J. Hopp, Mark L. Spearman, (2004) To Pull or Not to Pull: What Is the Question? Manufacturing & Service Operations Management 6(2):133-148.

Cultural Transmission at Toyota:


One of my favorite stories related to statistics is of Abraham Wald. During World War II, American military sought the help of the Statistical Research Group (SRG) for their bomber planes. The problem was how to reinforce the planes to improve the chances of survival in an attack. The story goes that the military had done an analysis of the damages on all the planes returned from attacks. The different parts of the planes were the fuselage, the wings, the tail and the engine. The question was where should the reinforcement be done on the plane, because more reinforcement meant more weight, which impacted the performance of the plane. The data showed that the most damage was found on the fuselage. The military wanted to start working on reinforcing the fuselage. Wald, however, cautioned against it, and advised on reinforcing the least hit part that was most vulnerable part of the plane. It turned out that this part was the engine. Wald’s logic was that the military was looking at the planes that got hit and yet managed to come back safe. The data that was most important was on the planes that did not make it back home safe. This story is often used to explain the survivorship bias – the logical error of using the cherrypicked data of the very few that made the cut while ignoring the very high numbers of those who did not make the cut.

My main takeaway from the Wald story is about looking at what is not there. Sometimes this information is the most important and yet it is not readily visible. I will try to use this concept with Lean. Lean is often perceived as a set of tools. When Toyota opened the doors for the rest of the world, many like the Military in the Wald story saw only what was in front of them – 5S, Kanban, andon cords etc. The unseen part, the culture of Toyota, the Toyota Way, was missed. One of the words that sticks out when one reads the first books on Toyota Production System is “rationality.” Rationality is coming up with innovative ideas to meet the required challenge primarily with what you got – with your wit and what you have on hand already. Rationality is doing just what is right. Rationality is the root of kaizen.

I am interested in looking at how Taiichi Ohno was able to develop the Toyota Production System and most importantly make “it” stick, over the generations. Taiichi Ohno was inspired by the challenge issued by Kiichiro Toyoda, the founder of Toyota Motor Corporation. The challenge was to catch up with America in 3 years in order to survive.  Ohno built his ideas with inspirations from Sakichi Toyoda, Kiichiro Toyoda, Henry Ford and the supermarket system. The two pillars of the Toyota Production System are Just-in-Time and Jidoka. Just-in-time or “Exactly-in-time”, as Ohno calls it [1], is the idea of producing just what is needed at the right time in the right quantity. The concept of Just-in-Time was the brainchild of Kiichiro Toyoda. Kiichiro Toyoda had written a 4” thick pamphlet that detailed his ideas of a system to produce every day exactly what was needed in the quantity needed. Piror to Ohno’s kanban concept, Toyota was already using tickets as part of Just-in-Time system. The concept of Jidoka was based on the automatic loom developed by Sakichi Toyoda (father of Kiichiro Toyoda). The automatic loom that Sakichi built also had a weft-breakage automatic stopping device, which ensured that the loom stopped when a thread breakage occurred. This allowed one operator to handle multiple looms at a time. Thus, we can see that the two pillars of Toyota Product System were based on the concepts of two parental figures in the Toyoda family.

Toyota Global’s website details the roots of Toyota Production System: [2]

The Toyota Production System (TPS), which is steeped in the philosophy of “the complete elimination of all waste” imbues all aspects of production in pursuit of the most efficient methods, tracing back its roots to Sakichi Toyoda’s automatic loom. The TPS has evolved through many years of trial and error to improve efficiency based on the Just-in-Time concept developed by Kiichiro Toyoda, the founder (and second president) of Toyota Motor Corporation.

Taiichi Ohno rose to the occasion of increasing the productivity of Toyota by developing a production system to improve productivity. The concept of Jidoka he learned from the Toyota Automatic Loom Works company, allowed him to have one operator man multiple machines at a time. He rearranged the facility in order to allow the process to flow better. By expanding on the Just-in-Time idea and the American Supermarket system, he developed a kanban system that ensured a pull system to make product only in the right quantity at the right time. There was a lot of resistance against his ideas. It was initially termed as the “Ohno system” instead of “Toyota Production System.” Ohno however had the full support of his superiors, Eiji Toyoda and Naiichi Saito [1]. They absorbed all the discontent and grumbling directed at Mr. Ohno from the factory and never mentioned to him. They only wanted him to continue finding ways to reduce manufacturing costs.

Implementing a production system like Toyota’s, can be viewed as a cultural transmission phenomenon in the organization. As the great population geneticist Luca Cavalli-Sforza puts it [3]Cultural transmission is the process of acquisition of behaviors, attitudes, or technologies through imprinting, conditioning, imitation, active teaching and learning, or combinations of these. Cavalli-Sforza expands on this idea [4]: the ability to accumulate knowledge by cultural means, that is by exchange of information between individuals within and across generations, is a powerful mechanism for adapting to new situations… Culture allows the spread of targeted solutions to problems affecting a population.

Cavalli-Sforza’s research indicates that the essence of cultural transmission is learning from other individuals. Ohno taught his methods to the production team most of the time by directly going to the required personnel. Ohno was famous for drawing a circle on the production floor and making the engineer or the supervisor stand in it to observe an operation so that he can “see” the wastes. Ohno’s methods were based on the “reality” present only at the gemba. He sometimes used trial and error methods. As he stated [1]: To confirm hypotheses through experimentation is not confined to the academic world. In industry as well, ideas are tested through continuous trial and error.

As I was reading Cavalli-Sforza’s works, one particular concept stayed with me. He noted that transmission through a social leader or teacher results in greater homogeneity in a population than transmission through a parental figure. The social leader has great influence over others in an organization. At the same time, the parental figure can have a long-lasting effect. [5]The culture created by the organization’s initial leaders forms a “genetic imprint” for the organization’s ontogeny; it will be clung to until it becomes unworkable or the group fails and breaks up. The two aspects of the cultural transmission from a social leader (Taiichi Ohno) and parental figures (Sakichi Toyoda and Kiichiro Toyoda) resonates well with any student of the Toyota Production System.  The cultural transmission over time allows for better ideas and practices to replace the less effective ones while at the same time maintaining the core concepts of the system.

Always keep on learning…

In case you missed it, my last post was Herd Structures in ‘The Walking Dead’ – CAS Lessons:

[1] Just-In-Time For Today and Tomorrow, Taiichi Ohno and Setsuo Mito

[2] Toyota Global Website

[3] Theory and Observation in Cultural Transmission, L. L. Cavalli-Sforza, M. W. Feldman et al.

[4] Cultural Transmission and Adaptation, L. Luca Cavalli-Sforza

[5] A Complex Adaptive Systems Model of Organization Change, Kevin J. Dooley

Conceptual Metaphors in Lean:

Vitruvian Man blueprint.

In today’s post, I am looking at conceptual metaphors in Lean. A Conceptual metaphor is a concept in conceptual linguistics, first introduced by George Lakoff and Mark Johnson in their 1980 book, Metaphors We Live By. They noted that:

Human beings structure their understanding of their experiences in the world via “conceptual metaphors” derived from basic sensorimotor and spatial concepts (spatial primitives and image schemata) learned during infancy and early childhood. 

Metaphors are normally thought of as a way to explain something further. Aristotle noted that metaphors made learning pleasant. “To learn easily is naturally pleasant to all people, and words signify something, so whatever words create knowledge in us are most pleasant.” However, the conceptual metaphor theory goes beyond the metaphor being just a linguistic/artistic phenomenon. The conceptual metaphor theory notes that metaphors are primarily used to understand abstract concepts, and that these are used subconsciously on an everyday basis. The conceptual metaphors are treated as an inevitable part of our thinking and reasoning. Lakoff and Johnson note that:

The essence of metaphor is understanding and experiencing one kind of thing in terms of another… Metaphors are fundamentally conceptual in nature; metaphorical language is secondary. Conceptual metaphors are grounded in everyday experience. Abstract thought is largely, though not entirely, metaphorical. Metaphorical thought is unavoidable, ubiquitous, and mostly unconscious. Abstract concepts have a literal core but are extended by metaphors, often by many mutually inconsistent metaphors. Abstract concepts are not complete without metaphors. For example, love is not love without metaphors of magic, attraction, madness, union, nurturance, and so on.

One form of conceptual metaphor is an “Ontological Metaphor” – a metaphor in which an abstraction, such as an activity, emotion, or idea, is represented as something concrete, such as an object, substance, container, or person. A good example of an ontological metaphor in lean is waste. We are taught that we should seek total elimination of waste in lean. We are giving a physical representation to the abstract concept of “waste”. Waste is an adversary that can hurt us, steal from us, and destroy us. To paraphrase Lakoff: (I have inserted Waste in his example)

The ontological metaphor of waste allows us to make sense of phenomena in the world in human terms—terms that we can understand on the basis of our own motivations, goals, actions, and characteristics. Viewing something as abstract as waste in human terms has an explanatory power of the only sort that makes sense to most people. When we are suffering substantial economic losses, WASTE IS AN ADVERSARY metaphor at least gives us a coherent account of why we’re suffering these losses.

It is also interesting to see how the concept of waste got translated as it was transplanted from Toyota to the West. Taiichi Ohno, the father of TPS, saw waste in terms of man-hours and labor density. Outside Toyota, elimination of waste was seen as a means to increase capacity, a pursuit of efficiency alone.

Labor density is the ratio of work and motion.

Work/Motion = Labor Density

In the equation, work indicates the action carried out to forward a process or enhance the added value. Ohno realized that the correct way to improve labor density is to keep the numerator (work) the same, while decreasing the non-value added portion of motion. The denominator is an impersonal motion and the numerator is work with a human touch. The act of intensifying labor density or of raising the labor utility factor means to make the denominator smaller (by eliminating waste) without making the numerator larger.

Kiichiro Toyoda, Toyota’s president in 1949, issued the challenge to catch up with the United States within three years. America’s productivity was thought to be eight or nine times better than Japan’s. Ohno realized that this was not because the Americans were physically exerting ten times more than the Japanese. “It was probably that the Japanese are wasteful in their production system”, Ohno thought. Ohno’s view was that the total elimination of waste should result in man-hour reduction. Toyota’s man-hour reduction movement is aimed at reducing the overall number of man-hours by eliminating wasted motions and transforming them into work. Toyota succeeded because they realized that elimination of waste was an expression of their respect for humanity. The respect of humanity portion may have gotten lost in translation when the ontological metaphor of “waste” was spread outside Toyota.

Employees give their valuable energy and time to the company. If they are not given the opportunity to serve the company by working effectively, there can be no joy. For the company to deny that opportunity is against the principle of respect for humanity. People’s sense of value cannot be satisfied unless they know they are doing something worthwhile.

Ohno’s first go-to training tool was to ask the supervisor to try doing the same work with less operators. The elimination of waste becomes easier when the operators have a visual control system for seeing waste as either time on hand or stock on hand, and when they avoid overproduction via Kanban. Ohno’s view of elimination of waste was to be effective and efficient by producing only what is needed. The idea of elimination of waste in the West may have become pursuing just efficiency and dropping effectiveness. The waste elimination can be viewed as a means to increase capacity, and this leads to the question – why should we stop at the daily required quantity of 100 units now that the improvement activities have yielded us more capacity to produce up to 125 units a day? Lean has become “doing more with less”, while Ohno’s goal was “doing just what is needed with less.” Ohno’s goal was being efficient and effective, even if it meant machines remained idle.

Final Words:

The term “Lean” itself is a conceptual metaphor. “Lean” refers to being fit, as opposed to being obese. In “Lean”, elimination of waste is about “trimming the fat”. The metaphor of “lean” represents the aesthetics of being beautiful and healthy – perhaps a notion of being in charge and knowing what needs to be done. This could be viewed as the Western philosophy of outwardly focus on external beauty, whereas the Eastern philosophy is more inwardly focused. In Japanese culture, the concept of harmony is imperative. This is part of the ‘respect for humanity’ side of the Toyota Production System.

I welcome the reader to explore the concept of conceptual metaphor. You may also like one of my older posts – Would Ohno Change the Term “Lean”?

Always keep on learning…

In case you missed it, my last post was Chekhov’s Gun at the Gemba: