Poka-Yoke is also known as mistake-proofing. When any problem is associated with a human error, it is important to tackle it with a contrasting error-proof solution. Poka-Yoke is the recommended plan of action in all cases where there is a dependency on human alertness for correctness.
Types of Human Errors:
- Forgetfulness (not concentrating)
- Errors in miscommunication (jumping to conclusions)
- Mistakes in identification
- Errors made by untrained workers
- Willful errors (ignoring rules)
- Accidental errors (distraction; fatigue)
- Errors because of the slow movement (delay in judgment)
- Errors due to lack of standards (these include both written and visual)
- Surprise errors
- Intentional errors (sabotage). This is the least common type of error.
People don’t usually commit human errors on purpose. On the contrary, they take place because of a weak system or a poor process design. Most importantly, keep in mind that even a 100% automated system will still depend on people to run them.
Therefore, try to eliminate human errors by installing a superior process or system design. Furthermore, the design needn’t always be a technological change or an invention. Instead, it can be as simple as adding a step or change in the process flow. Mistake proofing can be fun! It is exciting to discover ways to construct a situation where it becomes impossible to commit an error.
Poka-Yoke is the only way out when humans cause errors knowingly or unknowingly. Subject matter expertise plays a crucial role in developing an effective Poke Yoke system. Hence, you should make it a point to involve people from the R&D department!
Good, Better, and Best System: A Comparison between Poka Yoke and Other Systems
Below is a comparison of a good vs. better vs. best system. The best system is considered to be Poka-Yoke. Note that a good system shuts down when an error occurs. However, the best system results in a shutdown when an error is about to occur. Therefore, anticipation is key. While creating the best system may not be possible initially, continuous improvement will help you work towards the goal!
In a good system, the situation is such: an error has occurred, defects have occurred, a defect warning is signaled, a control/ feedback is given, and finally the system shuts down. On the other hand, is a better system, a defect is about to occur. Consequently, the system shuts down. However, the Poka-Yoke system runs on mistake-proofing. It prevents the error from occurring in the first place.
Nevertheless, remember that instilling a Poka-Yoke system isn’t the starting point. On the contrary, it’s evolutionary. It takes place over time so that one can attain the final goal of fulfilling ‘perfection’ – the fifth Lean principle.
