What are Jidoka and Autonomation
What is Jidoka and Autonomation
Jidoka is one of the principles behind the Toyota Production System (TPS), Autonomation or Jidoka is about having machines with “human” intelligence so that they stop when something is wrong. It is one of the principles that is probably least understood by many in the west and not implemented as thoroughly as it should be.
Originally Jidoka within TPS was about making automation more “human”, having machines that would stop and highlight a problem when it occurred rather than continuing blindly on with an operator sat there monitoring everything that was happening. This is known as Autonomation, automation with a human touch.
Later the principle of stopping when something out of the ordinary occurred was applied not just to the machines but to the whole production process so Jidoka became the practice of stopping the whole process when errors occurred.
Origins of Jidoka and Autonomation
In much the same way that most of the Toyota Production System can be traced back to previous works and initiatives such as Ford’s original Production Lines which were then improved on dramatically within Toyota, the birth of Autonomation and Jidoka can be traced back to before Toyota began to build Cars.
Before Toyota became Toyota, the Toyoda family were busy trying to build their textile industry, Sakichi Toyoda designed a loom that automatically stopped when the thread either ran out or broke. This meant that the machine did not continue on blindly creating a piece of cloth that then had to be reworked, or scrapped. This allowed them to not only reduce the amount of scrap and rework in their processes it also allowed them to have a single operator running several machines rather than sitting watching just one.
It is rumored that it was the sale of this patented technology to a textile company in Yorkshire in the UK that provided the capital that the Toyoda family required to start the Toyota Motor Company.
As the Toyota Production System progressed and Toyota grew they began to realize that they did not have to fully automate a process at great expense if they could get many of the benefits of automation from simple machines with a little built in intelligence that could inform the operators when something was going wrong, thus Jidoka began to be implemented in earnest.
The machines instead of requiring an operator to stand over them constantly observing them to ensure nothing went wrong were imbued with “intelligence” so that they stopped when something occurred out of the ordinary, or would not cycle if anything was incorrect when loaded etc. This meant that the operators instead of having to continually monitor the machines would only have to interfere with them on an exception basis, thus the operators could monitor several machines rather than just one.
Jidoka and Visual Management
Combined with aspects of visual management such as Andon lights Jidoka allows everyone to quickly see any problems on the factory floor quickly and easily and come running to fix them.
This means that costs are lower as fewer people are required, and the levels of technology used are lower than full automation so lower skill levels for the operators were required again meaning cost savings.
Jidoka Autonomation Video
How does Autonomation / Jidoka work
As in the loom originally sold to the UK, machines were designed to detect abnormalities in their running conditions so that they were stopped, in addition to applying Poka Yoke devices and ideas to prevent operation if components were incorrectly loaded or missed etc. Most of these ideas are very simple and inexpensive to apply and prevent the creation of defective materials which could then disrupt later steps in the process.
The whole point however is to stop the process whenever there is a problem, the operators are then only responding to the machines to reload or to fix problems on an exception basis. This allows everyone to focus their attention on solving these problems to prevent them from occurring again.
The application of Jidoka across the whole process is a natural progression of this tool, the operators being given the authority to stop the entire process if there is a problem, thus focusing everyone’s attention on problem resolution. In this manner problems are resolved as quickly as possible and not ignored or worked around without resolution.
Jidoka is One of the Pillars of Lean
The Importance of Jidoka
Jidoka is one of the most important pillars of the Toyota Production System and of course Lean. It is only by combining Jidoka, respect for people and Just in Time (JIT) principles that Toyota can truly achieve the success that they do.
Many companies in the west that are trying to implement Lean stop short of allowing their operators and machines being able to stop the whole production line when a problem occurs and thus do not instil the urgency and discipline required to solve the root causes of the many problems that plague us.
A JIT system requires that all parts of the process are reliable and produce defect free products when required. Any failure will cause the system to break down so people must be empowered to solve problems when they are highlighted by Jidoka or Poka-Yoke devices.
By implementing Jidoka as part of your Lean system you begin to drive out problems from your processes and achieve much higher levels of quality. Typically the use of Jidoka, Poka Yoke and other lean tools will achieve far better results than the often quoted six sigma levels of quality.
Stop the Line to Correct Problems
Jidoka Line Stop
If you go into any Toyota Car Manufacturing plant around the world you will be able to see that the operators are able to easily stop the line if they have a problem and have the authority and in fact are compelled to do so.
By stopping the line when a problem is encountered it focuses the attention of all involved in actually solving the problem rather than just continuing to live with it. Most companies that I have visited over the years have operators that conduct their own unofficial rework or "work arounds" just so that they can aid management by keeping production moving.
We live with problems and fail to deal with them as we are often too scared of not making the numbers; yet if we solved the problems we would be able to "make the numbers" so much easier and with a whole lot less effort on the part of everyone involved. However we are often too worried about the initial impact that allowing line stops would have.
Poka Yoke video
Jidoka: Poka Yoke
Poka Yoke or mistake proofing is a technique that is part of Jidoka as well as being a stand alone tool in it’s own right. The idea of Poka yoke is to design the process in such a way that it is impossible to process or create defective materials.
This can be achieved through simple ideas such as profiled locations in fixtures that will only accept the correct components, pins that will show if holes are missing or blocked, simple sensors to check if components are present or correctly located etc.
Poka Yoke devices should be simple and inexpensive, often the best devices are those devised by the operators running the process. If you are having to spend vast amounts of money on devices then you are probably not thinking hard enough or wide enough to solve the issue.
As with the autonomation aspects of a process or machine poka yoke should be introduced at the process design phase, use tools such as Process Failure Mode and Effect Analysis (PFMEA) to highlight potential failures and then try to design them out of the process.