Jidoka is a lean manufacturing principle which detects any defect automatically in a process & stops it by alerting the operator to fix the problem.
The following are the main stages in Jidoka
- Defect or abnormality detection
- Stop the process
- Take interim action
- Identify the root cause & prevent it
The Jidoka concept was developed by Sakichi Toyoda in the early 1900’s. Jidoka is one of the main pillars of Toyota Production System (TPS). It plays a key role in Lean implementation.
Whenever a defect or abnormality is detected automatically the process should be stopped. There are various reasons for the stoppage
One of the main reasons for stoppage of a process whenever you encounter a quality issue. If the defect is passed to further processing without detection, the value addition goes in vain. If defective products are produced it takes more resources & time to fix the issue.
Earlier the detection better the process. If there is a delay identifying the issue it may cause further damage. In total stopping the process at the origin of defect/problem reduces the follow-up costs & can be fixed easily.
Whenever we find problem with the process it has to be stopped irrespective of the quality of the product. These process issues gradually may further lead to more problems affecting the quality cost & safety in the process.
One of the common examples is material shortage which should be considered as a stop as this is an abnormality & time is wasted waiting for the material.
It is important that the process stops should happen automatically whenever there is an abnormality. If not detected automatically the costs to fix the problem would multiply. Poka Yoke is one of the tools that can be used to prevent the abnormalities.
After the process is stopped, we should fix it immediately wherever possible. If it is a maintenance issue do the maintenance, if it is a quality issue fix it. If you can fix the problem permanently it is better. If not quick fix & further investigate to find the root cause & prevent it from recurring.