Jidoka

What is Jidoka?

The forgotten Pillar of the Toyota Production System

 

Jidoka is the often forgotten pillar of the Toyota Production system and lean manufacturing yet it is one of the most important principles of lean that can help you achieve true excellence. Jidoka is about quality at source, or built in quality; no company can survive without excellent quality of product and service and jidoka is the route through which this is achieved.

 

Built in Quality

Jidoka; one of the Pillars of Lean and the Toyota Production System.

Jidoka

Jidoka; One of the pillars of Lean and TPS

 

Development of Jidoka

 

Initially Jidoka began its life with the invention by Sakichi Toyoda in 1896 of a simple device that could stop the shuttle on an automatic loom if the thread broke. This meant that it prevented the machine from not only creating defects but also alerted the operator to a problem which meant that one operator could now operate several looms rather than have to stand there watching just one in case something went wrong. This principle became known as Autonomation or automation with a human touch.

The sale of the patent for this invention to a UK mill provided the funding so it is said to fund the creation of the Toyoda families new business; Toyota.

But the principles that were applied to machines with Autonomation were soon applied to the whole process by Taiichi Ohno

 

 

 

 

Principles of Jidoka

 

The principle of Jidoka can be broken down into a few simple steps;

  1. Discover an abnormality
  2. STOP
  3. Fix the immediate problem
  4. Investigate and correct root cause

 

This principle is not just confined to use within machines through autonomation ; jidoka is visible in almost every aspect of lean manufacturing when you start to examine it. It is about building Quality into a process rather than inspecting for it at the end of the process, inspection still has a place even in Toyota, and despite what people think can still be a powerful way of preventing defects reaching the customer.

 

Jidoka; Line Stop

 

Every individual in a lean company such as Toyota has the authority, in fact the requirement to stop the process should they discover an abnormality, this is the way that defects and problems are highlighted and actions are taken. This is a step that many western companies fail to make as they fear a loss in productivity due to lines being constantly stopped for “minor” problems.

This fear however undermines one of the most important tools of Lean Manufacturing; Jidoka, through jidoka we don’t just stop the process, we highlight the problem, correct it and then tackle root cause to prevent the problem ever happening again.

So through a sometimes initially painful series of line stops we start to remove problems from our process, within a short period of time the number of line stops begin to reduce as problems are removed and productivity begins to improve as root causes of problems are removed.

Within companies such as Toyota line stop is a way of life, if an operator detects a problem they pull a cord or push a button to stop the production line at the end of that production cycle. This lights up an Andon board which alerts the team leader or supervisor who will immediately rush over to help solve the problem. If it can be easily corrected then they do so and restart the line, otherwise they call in whatever support is required to solve the problem.

 

Jidoka Problem Solving

 

Many machines produced today have incorporated autonomation ideals in their design as they are seen now very much as being common sense, and with today’s technology are inexpensive and simple to incorporate into a machines design. Where we tend to fail is not having the problem highlighted but in taking action to correct the problem and solve root cause. It is important that we not only give our operators and supervisory staff the authority and responsibility to stop production when they find a problem but that we also train everyone in appropriate problem solving tools to enable us to remove the root cause of the problem. We then need to ensure that any process documentation is updated to incorporate the changes and that we communicate those changes across similar processes and products to spread the learning.

 

 

Jidoka and Lean Manufacturing tools

 

The first step of Jidoka is that of detecting an abnormality, so for autonomation the machine uses simple sensors to detect a problem and then stops and highlights the problems for the operator. For line stop the operator detects an abnormality and stops the line and highlights the problem for all to see on an andon board.

Other Lean tools use various aspects of visual management to highlight abnormalities, consider 5S; we identify the locations for tools, components and work in progress, if we see things that are not in their allocated place we have seen an abnormality and should take action. Why do we have missing tools? Why are additional stocks being stored where they should not be?

Other tools such as Kanban will also quickly highlight problems, why have these products been moved without Kanban authority?

Look at TPM (Total Productive Maintenance), we replace machine covers with transparent covers that let us see when we have problems more clearly, we use Kamishabi boards to schedule maintenance and other tasks, if cards are not turned we can see at a glance that we have problems.

Our daily attainment figures displayed at the workplace show what the production targets are and our current attainment, if we have not met target why not?

Lean relies on Jidoka principles across the various tools and gets us to use visual management techniques to highlight whenever an abnormality occurs for us to take action. As team leaders, supervisors and managers we need to keep our eyes open as we walk through our workplace for these abnormalities and follow through on the Jidoka principles;

  1. Discover an abnormality
  2. STOP
  3. Fix the immediate problem
  4. Investigate and correct root cause

 

Jidoka Video

 

 

 Additional Jidoka References

You can see what Toyota has to say about Jidoka here or you can also have a look at lean.org for their definition or have a look at this interview with someone who “grew up” in Toyota with Jidoka.

Jidoka Reference Books

Working with Machines: The Nuts and Bolts of Lean Operations with Jidoka
JIT Implementation Manual — The Complete Guide to Just-In-Time Manufacturing: Volume 5 — Standardized Operations — Jidoka and Maintenance/Safety – Kindle Version

 

Jidoka; autonomation, line stop, Poka yoke and visual management are very important to ensure quality at source or built in quality and to protect our customers and businesses; used correctly Jidoka will drive improvement through all aspects of our business. If you have any questions or observations about Jidoka please feel free to leave comments below.

 

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