Guide: Jidoka

The concept of Jidoka, important to lean manufacturing, represents the combination of human intelligence and mechanical automation. Originating from Sakichi Toyoda’s innovations in the textile industry, Jidoka has evolved into a cornerstone of the Toyota Production System. It’s more than just machinery performing tasks; it’s about machines detecting abnormalities and humans stepping in to ensure quality.

This principle shifts the production focus from quantity to quality, endorsing a stop-and-fix approach to defects, ultimately leading to a zero-defect production line. Embracing Jidoka means embracing a culture where every employee plays a crucial role in quality control.

Table of Contents

The Origin of Jidoka

Jidoka, a principle that is understood as “autonomation with a human touch” when translated from Japanese, goes beyond mechanical automation. The principle integrates the human capacity to observe and reject irregularities with the precision and consistency of machines. The principle aims to create a system in which a person and machine work together to achieve a zero-defect production process.

In traditional manufacturing, the focus is usually on the output, aiming to produce as many products as possible. This approach can lead to the creation of defects and a reduction in the overall quality of the outputs in the process. Jidoka interrupts this pattern by ensuring quality is the central focus of the production process. When a defect is detected, the process is stopped, allowing for immediate intervention.

This may sound counterintuitive, as the downtime could be at a higher cost than a single defect. However, consider that the first defect is the first of many in the process that has gone out of control. Alternatively, in a car production facility where the output is worth many thousands, a single defect is worth stopping the line to understand the issue and correct it rather than continuing the line that is at risk of producing further defects.

Taking this approach results in the following:

  • Reduces waste associated with defects
  • Lowers the cost associated with rework and returns
  • Ensures that only products meeting quality standards reach customers

The Human Element of Jidoka

One of the most interesting parts of Jidoka is how it gives employees of the business the responsibility to take ownership. While a process may be automated and systems can detect defects, it is human knowledge, skills, and experience that analyze, troubleshoot, and improve the production process. Employees are trained to understand the intricacies of the machines they operate and are encouraged to suggest improvements. This element is important when transitioning from just identifying defects to preventing them in the future.

The Evolution of Jidoka

Sakichi Toyoda‘s innovation in Jidoka was important because it demonstrated the potential of integrating human problem-solving abilities with the reliability of machines. After an initial success in textiles, this principle was expanded and refined by his son, Kiirchiro Toyoda in the automotive processes of Toyota. Over time, Jidoka has become one of the two main pillars in the Toyota Production System (TPS)

The Toyota Production System House

The Four Stages of Jidoka

The four stages of Jidoka represent a cycle that ensures quality and efficiency in the manufacturing process

Stage 1:Detect the Abnormality

Detection is the first and most important step in the Jidoka Process; without detection, issues cannot be identified and resolved. Therefore, is is important to have robust detection methods within a process that identifies abnormalities.

This can be made possible with the following:

Sensors and Devices: Monder manufacturing equipment, with the inclusion of Industry 4.0, often has sensors and other devices that are capable of detecting a wide range of issues, from out-of-spec temperatures to checking the weigher that weighs each product in a food factory to ensure it is within customer specification. In the industry, there are an almost unlimited number of examples of machines with sensors.

Software Monitoring: Software systems that can monitor the performance and output of machines and flag any data that indicates a potential issue, such as drops in production speed or increases in error rates of product specs exceeding specification limits on control charts.

Stage 2: Stop the Process

The next step if a defect is detected is to stop the process. This can be controlled automatically in some cases with some of the following:

Automated Shutdown: Machines equipped with Jidoka-capable devices can automatically shut down when a sensor identifies a defect and triggers an alert.

Andon Systems: Another method is with Andon which is a Visual alter system which can be activated to signal that an issue has been identified, prompting a response from a response team.

AndonSystem

Empowerment of Workers: Workers can be empowered to stop the production line by pulling an Andon cord or pressing a stop button when they detect an abnormality, regardless of their position in the company hierarchy.

Stage 3:Fix or Address Immediate Concern

Once the line has been stopped due to a defect, the next step is to fix or address the immediate concern. These immediate fixes should prevent the problem from continuing or recurring in the short term.

Quick Response: Teams are trained to respond quickly to Andon alerts, often following a set of standardized procedures to address common issues.

Temporary Measures: Sometimes a short-term fix is applied to keep the process moving while a more comprehensive solution is developed. This could be a quarantining product or running the production line slower with additional checks in place for a while.

Quality Checks: After the immediate fix, the product is usually re-inspected to ensure that it meets quality standards before proceeding.

Stage 4: Investigate and Correct Root Cause

The final stage of Jidoka is about finding and fixing the underlying problem, which is crucial for long-term improvement. This can be done using Root Cause Analysis (RCA) and techniques like 5 Whys Analysis or Fishbone Analysis to uncover the root cause of the issues.

It is recommended that this process is done with cross-functional teams as they are able to look at the problem from multiple perspectives, including design, engineering, operations, and quality control.

The insights from the RCA can lead to changes in the process which could include redesigning parts, updating machine programming, improving training, or revising maintenance schedules. Once this has been done, the short-term fixes can be removed, and the process can continue to run as normal with the long-term fix in place.

Conclusion

Jidoka transforms manufacturing into an intelligent, responsive process that prioritizes quality over mere output. This approach champions the idea that stopping to correct a single defect prevents a multitude of future errors, saving costs and maintaining high-quality standards.

It requires a combination of advanced technology with the irreplaceable human element, fostering a proactive workforce that can detect, halt, and rectify issues. By committing to this principle, businesses can achieve sustainable excellence, where the prevention and correction of errors are as systemic as the production process itself. Jidoka, therefore, is not just a practice but a philosophy that underpins the relentless pursuit of perfection in manufacturing.

References

A: Jidoka is a principle developed by Toyota as part of the Toyota Production System (TPS). It focuses on automating quality control within the production process by enabling machines and operators to detect abnormalities or defects. The goal of Jidoka is to stop production immediately when an abnormality is identified, preventing the production of defective products and ensuring higher quality standards.

A: Jidoka differs from traditional manufacturing approaches in that it emphasizes the automation of quality control. Instead of relying solely on final inspections, Jidoka integrates abnormality detection mechanisms throughout the production process. It allows for immediate detection and response to abnormalities, reducing the chances of producing defective products and enhancing overall quality and efficiency.

A: Common abnormality detection mechanisms in Jidoka include visual inspection, sensors, gauges, and automated systems. Visual inspection involves trained operators visually examining products for irregularities. Sensors can monitor parameters like temperature, pressure, or vibration. Gauges and measuring devices ensure dimensional accuracy. Automated systems employ data analysis or machine learning algorithms to detect abnormalities.

A: Andon systems are an integral part of Jidoka implementation. An Andon system is a visual display or signal that alerts operators and supervisors when an abnormality is detected. It provides immediate visibility and prompts action to address the abnormality. Andon systems facilitate communication and collaboration among the production team, helping to identify, analyze, and resolve abnormalities in real-time.

A: Operators play a critical role in Jidoka. They are trained to operate abnormality detection mechanisms, interpret abnormalities, and effectively use Andon systems. Operators are empowered to stop production when an abnormality is detected and escalate issues for further investigation and resolution. They are also involved in problem-solving activities, identifying root causes, implementing corrective actions, and preventing future occurrences of abnormalities.

A: Jidoka offers several benefits to an organization. It helps maintain high-quality standards by detecting abnormalities early and preventing the production of defective products. This leads to improved customer satisfaction and reduced costs associated with rework or customer returns. Jidoka also promotes a culture of continuous improvement, empowering operators to take ownership of quality control and problem-solving. By integrating Jidoka, organizations can enhance product quality, increase operational efficiency, and foster a proactive approach to quality management.

A: To ensure the effectiveness of Jidoka implementation, organizations should regularly monitor and evaluate the system’s performance. This includes tracking performance indicators, defect rates, and customer feedback. It is important to gather feedback from operators, supervisors, and other stakeholders and make necessary refinements to the detection mechanisms, standard operating procedures (SOPs), and problem-solving protocols. Continuous monitoring, evaluation, and refinement are key to optimizing Jidoka and achieving continuous improvement in product quality and operational efficiency.

Author

Daniel Croft

Daniel Croft

Daniel Croft is a seasoned continuous improvement manager with a Black Belt in Lean Six Sigma. With over 10 years of real-world application experience across diverse sectors, Daniel has a passion for optimizing processes and fostering a culture of efficiency. He's not just a practitioner but also an avid learner, constantly seeking to expand his knowledge. Outside of his professional life, Daniel has a keen Investing, statistics and knowledge-sharing, which led him to create the website learnleansigma.com, a platform dedicated to Lean Six Sigma and process improvement insights.

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