Jidoka

Jidoka is a solution on production line that empower workers to stop production process immediately in case of any quality problems. After stopping the line, workers and managers have certain time to solve the problem. This limits number of defect products. The first Jidoka implementation was made by Sakichi Toyoda in 1902. He constructed a utility that stopped the loom when the thread was broken. It is regarded as the first part of Toyota production system.

In order to be able to stop the production line, workers need to know the quality of products and have technical possibility to stop the line. In order to provide workers with the information, automatic or manual quality control appliances are installed, which check all or chosen products.

Close to each workplace should be installed a button, which stops whole production line or some part of it (depending on used technology). Usually there is a time limit set by top management, in which the problem must be solved. After that time the production must start. Therefore, this solution is not intended to solving sophisticated problems.

Jidoka is related to Andon - the information system that helps workers to spot the problem immediately, even when they are far from the machines.

Jidoka is one of Lean manufacturing pillars, together with: Konnyaku stone, Poka yoke, Hansei, Andon, Just in time, Heijunka, Kaizen, Genchi genbutsu, Nemawashi.

Autonomation

Autonomation is a feature of machine that allows using Jidoka. It is described as intelligent automation. The autonomation can include:

• automatic problems detection,
• automatic stop,
• automatic fixing of product,
• presenting information about possible causes and countermeasures.

Thanks to automatic detection, workers don't have to stand close to the machine. It allows them to monitor many machines. It is important on modern production line, where workers perform only several operations. In order to achieve such effect, the operation of machines has to be harmonized. The Single minute exchange of die (SMED) method is used for this. Autonomation is important when using Just in time. It's also important part of Lean manufacturing systems.

Sometimes Jidoka and Autonomation terms are used interchangeably.

Requirements of Jidoka

Example of jidoka/andon system

In order to work properly, Jidoka requires:

• appliances that enable workers to stop production
• organizational solutions that help solve problems quickly
• relatively small number of defects, otherwise Jidoka will stop production too often
  • machines in good condition
  • preferably 5S method
  • defects-proof design
  • defects-proof technology

Benefits of Jidoka

The main benefits are:

• to avoid the spread of bad practices
• no defective products produced
• to add human judgment to automated equipment
• to minimize poor quality
• to make the process more dependable
• to have problems clearly identified so that Kaizen can be accomplished
• to give the employee responsibility and authority to stop production
• to prevent equipment breakdown
• high-quality products and improvement in productivity.

Examples of Jidoka

• Visual checks: Visual checks are an important part of Jidoka. Visual checks involve inspecting products and components of products at various stages of production to identify potential issues and defects. This involves workers and/or machines visually inspecting parts, components, and products at various stages of production to identify any potential issues.
• Red flagged products: This is a system that flags products that do not meet quality standards. These flags can be both physical flags or virtual flags that alert the production line or workers that the product does not meet quality standards.
• Sensors: Sensors can be used to detect errors on the production line. These sensors can detect physical errors, such as incorrect dimensions, incorrect parts, incorrect assembly, etc. and alert workers of any issues. This allows for quick resolution to any issues that may arise.
• Error proofing: Error proofing is a type of Jidoka that involves designing processes in such a way that potential errors can be easily detected. This allows for quick and easy resolution of any potential errors that may arise. Examples of error proofing include the use of fixtures, jigs, and other tools to ensure that parts are assembled correctly and that components are correct.

Limitations of Jidoka

Jidoka is a solution on production line that empower workers to stop production process immediately in case of any quality problems. Despite its important role in quality management, Jidoka has certain limitations. These include:

• The cost associated with Jidoka implementation may be high, especially for large companies.
• Technical issues might arise during Jidoka implementation.
• Workers should be trained properly in order for Jidoka to be effective.
• Jidoka does not guarantee that all the defects can be detected and corrected.
• The response time for solving the problem should be predictable in order for line to remain productive.

Other approaches related to Jidoka

In addition to Jidoka, there are other approaches that can be used to limit number of defect products on production line. These approaches are:

• Kaizen - it is a Japanese concept that involves continuous improvement of processes, products and services. It is designed to eliminate waste and increase efficiency.
• Kanban - this is a visual system that is used to control, monitor and optimize the production process. It is used to manage production levels and enable smooth flow of materials.
• Standardized Work - it is a set of procedures that are used to ensure consistent performance, quality and safety of manufacturing processes.

Overall, these approaches are used in combination with Jidoka to limit number of defect products and improve quality of the production process.

Jidoka — recommended articles

Poka yoke — Line balancing — Quality control — Konnyaku stone — Single minute exchange of die — Muda mura muri — Quality assurance — 7 wastes of lean — Computer integrated manufacturing

References

• Basic Toyota Production System Handbook (PDF)
• Baudin M. (2007), Working with Machines: The Nuts and Bolts of Lean Operations with Jidoka, Productivity Press, New York
• Berk E., Toy A.Y. (2009), Quality control chart design under Jidoka, Naval Research Logistics, Vol. 56, Iss. 5
• Damanpour, F. (1998), The impact of culture on management; A comparison of Japanese versus U.S management, Advances in Competitiveness Research
• Womack, J.P., Jones, D.T. and Roos, D. (1990) The Machine that Changed the World: The Triumph of Lean Production, New York, Rawson Macmillan
• Wong, V., Saunders, J. and Doyle, P. (1987) Japanese Marketing Strategies in the United Kingdom, Long Range Planning, vol. 20, no.6, p. 54-63

Author: Slawomir Wawak