Lean Manufacturing and the Brain

This week I learned that within the three pounds of spongy flesh that is the human brain there are 1.1 trillion cells, 100 billion neurons and 10 x 10 to the millionth power of possible neuron connections. This number makes my brain hurt. The book also described the human brain as having three main functions: regulation, learning and selection. The parallels to a lean manufacturing immediately struck me.

The primary function if the brain is regulation of the body. The brain inhibits or excites various bodily functions, controls actions, manages various starts and stops. A series of simple chemical on-off signals at the level of neurons combine in a staggering number of ways to allow us to do everything from dance the jig to dig up buried civilizations. Lean manufacturing is at one level a production controls system that stops overproduction and starts production based on customer pull. Signals are simple and local, green lights for go and red for stop.

Taiichi Ohno likened the Toyota Production System to establishing an autonomic nervous system within the factory. Just as we viscerally react to signs of danger to withdraw our bodies from danger or respond to stimuli even without being conscious of doing so, lean manufacturing establishes systems that are intended to cause similar responses. The downstream pull or kanban system is one example, the andon and problem response system is another. This fundamental shift from a conscious command-based production control approach to a subconscious stimulus-based production control system is another parallel between lean manufacturing and the brain.

Learning is the second function of the brain and this is accomplished by making new circuits and connections between the 100 billion neurons. Learning and forgetting happens as the degree of repetition strengthens or weakens these connections. Lean manufacturing requires that we set up experiments and learn by constantly changing for the better. There is no finished state in lean manufacturing, only the current state, the unattainable ideal condition and the drive towards it. This drive keeps us learning, and sustaining a lean system requires learning from our mistakes and solving problems.

Using the third function of selection, the brain references from memory those experiences that have worked out well or not so well in the past to consciously guide our actions. This could be described as our guiding principles, values or even human wisdom. We select good over bad, better over good, value over waste. In lean manufacturing terms this is the practice of reflection, or the human brain’s conscious comparison and reasoning through what is working and what is not.

Another way to think of this is the closing of the feedback loop of continuous improvement, the AP part of the PDCA cycle.

Even in a pull-based lean business model decisions don’t make themselves, but the structure of a lean system can make it difficult or even impossible to make bad decisions in certain cases. This is the essence of mistake proofing, limiting capacity or space to create WIP, and disconnecting automation or software that drives overproduction in favor of reactive systems that are based on proven principles, such as pull.

Kaizen is the act of making small changes in the physical world so that we learn to improve, learn to make better choices, to build and regulate better processes. When a person learns an instrument, a language or nearly any skill it is the wiring together of some of the 100 billion neurons as a result of repetition that results in mastery. This is why kaizen, or repeated small steps towards improvement, is so important. The primary resource for kaizen is human brains.

As with the 100 billion neurons with their 10 x 10 to the millionth possibilities, in a lean operation everything is connected and everything keeps changing. The traditional direction of improvement is to isolate, stabilize and shield from risk. Unfortunately no situation is every completely stable and disconnecting parts of the system in order to buffer or minimize risk simply removes stimuli. A lack of stimuli unwires our neurons in the brain, and likewise when we improve by covering up problems we are learning to manage the wrong way.

Lean manufacturing is a boring topic after a point, but the brain is ever fascinating. Then again look who is telling me this.

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