JIDOKA: Autonomation Definition & Examples
Jidoka has had many interpretations by various practitioners over the years. Some companies have stuck to the meaning of giving machines human-like intelligence. Jidoka can also be defined as the act of stopping processes when something goes wrong.
In the autonomation sense, Jidoka involves having special components within machines that stop the process when either of the following conditions are encountered:
- The target production goals are met
- Poor quality product
- Machine malfunction
The ultimate goal of this kind of autonomation is to prevent workers from constantly manning machines and give them the flexibility to operate more than one equipment. There is a close resemblance of this system with poka-yoke as espoused by its creator Mr Shigeo Shingo.
In this type of autonomation, an entire process is stopped when a problem occurs. It instils in the workforce a mental mind-set of stopping to correct problems and is a key tenet of the continuous improvement mentality.
It has been hard to transfer this thinking from the East to the West due to a number of reasons. These include:
- Poor interpretation into normal language of terms that are primarily Japanese in origin
- The original conditions that made the concept attractive are slowly fading away as machines become more efficient in performing their function
- Lack of courage to stop lines when errors occur
- Confusing autonomation and automation – two very different concepts
What is Jidoka? : Definition and Meaning
Jidoka is a quality control principle that gives machines or processes the ability to detect and report abnormal conditions.
Also known as autonomation, it bestows upon machines and processes a human-like intelligence in order to prevent avoidable defects from being produced. The concept revolves around building-in quality into processes so as to get quality right the first time. It can be considered as a quality assurance tool that automatically detects problems, stops the process and alerts the system so that corrective countermeasures can be made to avoid future occurrence of the same problem.
It is a way of thinking and principle of production that forces workers in any industry to constantly think of ways of improving the quality of products and services.
Origin of Jidoka
The principle was first used by the founder of the Toyota Group, Mr Sakichi Toyoda. He had developed the first automatic loom in 1896 in which he incorporated devices to stop the machines when quality issues such as broken threads occurred. Other devices that Sakichi Toyoda incorporated into his loom were:
- Loom supply device
- Automatic Shuttle changing devices
These devices increased productivity and quality in cloth production, which until then had been a very laborious and time consuming activity. The Autonomation concepts that were applied on the loom allowed for automation with a human touch because the machine stopped on its own when it detected an abnormality.
This led to improvement in quality and productivity because one operator could operate several machines effortlessly. Before the application of this concept, every machine had to be constantly monitored by a human being, which was a waste of time or muda.
Can machines in your organization detect errors?
Pillars of Quality Assurance
Jidoka is supported by four key components of quality assurance:
- Genchi genbutsu: This Japanese term means 'going to the source' of a problem to see it first hand. It is a necessary activity for acquiring an intimate understanding of the problem before setting out to solve it.
- Andon - These are signalling devices within the Jidoka system that give an alert when an abnormality occurs. Line operators have the authority to stop the line when a problem occurs, while management have the responsibility to ensure that the problem has been solved before restarting.
- Standardization - Standards are the basis of continuous improvement, quality and consistency. The use of standards ensures smooth production flow.
- Mistake-proofing- Poka yoke devices within the production process are aimed at preventing errors from occurring in the first place.
These four concepts are the foundation for successful implementation without which the program will fail. Autonomation is not an aim in itself, but is part of a comprehensive lean thinking philosophy that incorporates a variety of tools to achieve a truly lean enterprise.
Understanding the Autonomation Philosophy
Jidoka is a device to auto-stop a process so as to prevent a problem or defect from occurring. It is a tool for extending the value adding activities of operators by greatly multiplying their expertise and efforts while relieving them of monotonous tasks.
Taichi Ohno compared autonomation to the body’s autonomic nervous system that controls breathing, heart beat and other functions. It keeps the system functioning without any conscious attention until a problem occurs.
Autonomation provides a balance between human actions and machine actions and can be divided into four distinct actions:
- Detection of abnormality
- Stopping of the process
- Fixing or correcting of the immediate condition
- Investigation of the root cause and installation of appropriate countermeasure
Step by Step Implementation
An organizational system is never static and should be continuously evolving. The same applies for autonomation which is a continuous cycle of learning and improvement in response to different situations that may be encountered in the production process. The Jidoka cycle involves the following steps:
- Detect the problem - There are many ways of detecting problems with the jidoka principle in mind. These include devices inside of machines that detect errors, setting of takt time standards, kanbans and visual controls. Missing kanbans will be a sign that there is overproduction or non-compliance with set standards. Visual controls will communicate the problem when it occurs.
- Stop the process - Once the visual controls have communicated the presence of a problem, this triggers the action of stopping the line to investigate. As drastic as it may seem, the concept of stopping the line when an abnormality occurs is necessary so as not to pass defects to the next process.
- Correct immediate condition - Temporary countermeasures are taken so that production may continue. These may include increasing staff, kanban or work-cells. Care should be taken to prevent temporary countermeasures from breaking the production system that is in place. Supervisors should monitor these so as not make staff lose faith in the production system.
- Do 5 Whys analysis - A root cause analysis is carried out to get to the core of why the problem occurred. Temporary countermeasures were used to cover the surface problems so that production can continue uninterrupted. By asking the 5 whys, the deeper causes of the problem are brought to the surface.
- Implement corrective action - After the real cause of the problem is found, countermeasures are developed that will prevent recurrence of the same problem.
Detection of problems within the process and stopping the process are functions that can be done by machines. In fact, autonomation aims at separating the machine functions from the human functions so that the operators are left to do their value added work.
Before these improvements, the operator constantly needed to watch over machines and this resulted in low productivity and morale due to the monotonous nature of the task. Now the operator can load the machine, attend to another machine and come back to reload the machine.
When there is a quality issue, the machine will raise an alarm and the human operators will need to attend to the problem before any production can resume.
Jidoka Tools: Andon Line Stop
A lean manufacturing system ultimately results in the reduction of inventory and capacity buffers. Because of this, there is little room for errors as these would result in unnecessary downtime across interrelated processes.
Jidoka is a way of raising the alarm before problems become bottlenecks to the efficient operation of processes. That alarm in lean manufacturing is called an andon which is a device that originated at Toyota. The andon signal is usually a light, sound or any other signal that is raised by process operator whenever a quality problem is detected.
Andons are meant to stop the line so that problems can be addressed. It may appear like a bad thing to stop the line, but the culture of addressing problems before they are passed on ultimately saves time and money. This is because ignoring problems so as not to sacrifice production time will eventually cost more because the problems will become too big to ignore.
Jidoka Examples in Manufacturing
The following are a few examples of devices which are used for autonomation that can be found in manufacturing as well as daily situations. You will not how quality of the process or product is assured through detection and stopping to allow for corrective actions to be made.
- Tension detector on a coil feeder stops feed when there is improper tension on the machine
- Sensor to check for a part that is out of position stops the machine when the part is misaligned. The operator then has to re-align the part before the production process can continue. This kind of device helps in improving the quality of products by reducing the defect rate
- Proximity switch lowers a pile stacker as the pile increases or stops the machine when it is too high
- A sheet detector raises the print cylinder when there is a missing sheet in a printing press machine
- Presence sensing devices are safeguards for automatic feed machines. They have a sensing field that when broken stops the machine. These light curtains are more effective than other devices as they are not dependent on the operators’ acceptance of the device
- Surge protectors on the national grid protect power consumers from fault currents. Surges by lightning or contact between power lines can result in short circuits which cause excess power being drawn from the grid in a rapid manner. The surge protector detects excess current and absorbs it so as to prevent that excess from moving down the grid
- Apple uses a QR code on its products to track them during the production and post-production period. The tracking enables it to know which parts are working and which ones are not. This helps the company improve the performance of the devices over time
- Product recall procedures that triggers immediate stoppage of the production line. Though the system aims at capturing errors before they affect the final product quality, some errors may eventually slip through the tight controls. The recall procedure is a final stop gap measure to capture the error before it reaches the customer
Chaku Chaku: Load Unload Load
Chaku-chaku is a Japanese term that is literally translated as “Load-Load” and involves the efficient use of machines by arranging them in such a way that the operator can man as many as possible at the same time.
Chaku-chaku has been carried out in many lean organizations and has resulted in greater efficiencies within the workplace. These efficiencies are realized because fewer operators are required to produce the same number of products.
While there are many definitions of Jidoka, the definition that is most appropriate is autonomation. Just like many other lean manufacturing terms, the word Jidoka is Japanese in origin and can be traced back to Japan in the early twentieth century. The term got prominence when Sakichi Toyoda who was one of the foremost inventors in Toyota, developed a solution to the breaking of threads in looms.
The device was such a game changer in how factory workers handled errors in production because they now did not need to constantly monitor their machines as they reported errors and stopped them before they got out of hand. This lead to an improvement in quality of the final product because errors were corrected before they moved along the value chain.
The Jidoka concept has various been described as autonomation with a human touch by lean manufacturing practitioners. While this definition is quite apt, it does not really go deep enough to explain what the concept is really all about. Jidoka involves detecting errors or defects in any process, rectifying the defect and then investigating why the problem occurred so as to come up with permanent countermeasures.
In organization where Jidoka has been successfully implemented, you will find that there are many signalling mechanisms within the shop floor. These device alert the workers that the machine or product has a problem and then stops the process. Shop floor supervisors then work together with other employees in the investigation process where they try to find out the root cause of the problem. Once the root cause has been identified, the workers then develop countermeasures in a structured way so that there is a little likelihood for recurrence in the future.
Experienced lean companies will tell you that it is one of the most important pillars of the lean manufacturing paradigm. Without autonomation, all other parts of the system will not be sustainable and will eventually crumble. In fact, lean companies will not have a quality control department but rather quality thinking is engrained in the workers and in the processes.
The necessity for constant inspection is removed when such a system is in place, leading to better flow of material within processes, lower inventory and general improvement in the bottom line of an organization. Many inspection steps will become redundant after implementation of autonomation and will only be left to the final step where dispatch to the customer is taking place.
While the technology needed to implement the concept is now widely available, it is surprising that many companies are still finding hard to deploy it. This is slowly changing as case studies continue showing an amazing transformation when it is introduced – workers are themselves surprised that they do not need to constantly watch over machines like before.
When Jidoka is properly implemented, the workers can be easily be redeployed to perform such actions as preventive maintenance, 5S housekeeping, training as well as Kaizen workshops. This will have a definitely positive effect on the organization and the lean transformation will move even faster with everybody playing a positive role.
The word jidoka comes from Japanese and literally translated, it means ‘automation with a human touch/ intelligence’. It is a deeper way of looking at automation because machines are able to detect and to report any abnormalities that occur within process. It is in effect giving machine the same kind of intelligence that you would find in a human being.
Origin of Jidoka
Jidoka originated in Japan as a way of solving quality issues that were keeping productivity below the level required for industrial take-off. Sakiichi Toyoda, the founder of the Toyota Group, noticed that the traditional looms his parents were using had a high rate of defects caused by breaking of the thread.
The looms continued producing even after this error and this caused the final product to be defective and requiring rework. What Sakiichi Toyoda did was to include in the design of the automatic looms clever devices that automatically stopped the machines when the thread broke, quickly changed the shuttles and fed the machines without stopping them.
This concept is the origin of Jidoka as we know it today but the concept goes much deeper than that. It is really a principle that can be applied to any manufacturing situation and aims at attaining product excellence through automating the error detection and correction process.
Jidoka has many applications and this article will aim at showing a few examples so that understanding the concept becomes easier. Remember that Jidoka is more than just a mere tool- it a way of thinking about how to get it right the first time.
Application of Jidoka
Jidoka, as applied to machines, involved first the detection of the problem, alerting the operators that it has occurred, stopping the line, finding out why the problem occurred and finally developing countermeasures to ensure that recurrence does not occur.
Detection mechanisms include using time as a triggering mechanism in that if the standard cycle-times are not achieved, it is serves as a clear indication that there is a problem. Another way detection of errors can be achieved is through the use of kanbans. For example, if materials arrive at work stations without kanbans, it could be an indication that standard inventory levels have been breached.
But detection is only a first necessary step - - after an error has been noticed there needs to be a concerted effort to find out the root cause as well as a way of creating countermeasures to prevent the problem from happening again.
Supporting the Jidoka system requires that there is a relentless focus on the elimination of waste through thorough understanding of the real situation at work. Visual aids are also important in supporting the system because they provide an effective means of communicating issues across processes.
Another important prerequisite is the creation of standards once countermeasures are developed. These standards serve as a means of training and also as a reference point for further improvement.
Finally, Jidoka must be supported by error-proofing mechanisms which automatically prevent errors without the intervention of operators. This removes a lot of time is figuring out the correct way to perform a function which frees up the processes to concentrate on value-added activities.
Though jidoka has come to be known as automation with a human-touch, a better way of describing it is people-centred improvements which are more focussed on how human beings and machines interact with the aim of producing quality.
The notion that machines can entirely replace human beings is beginning to lose favour as companies realize that people are the most important factor of production because they have intelligence that is had to replace.
A recent article in Industry Week magazine explains this new realization and argues that people are taking back jobs from robots at Toyota.