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 ultrsstable 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.
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: