Poka Yoke method – quality assurance without quality control

August 5, 2020


Share on Social!

Many of us have a Mobileye device in our vehicle, we are familiar with the annoying beeping that is heard when we change lanes, get to close to a car or any other mistake that is caused manly from exhaustion, not paying attention or even the afternoon glare. Though we often ignore the device, it has also saved quite a few of us from impending accidents.

Remember the Japanese, the champions of punctuation that we talked about in the previous post? It seems that they have made their mark regarding handling human errors, the same errors we fix by installing Mobileye devices.

One of the known methods in the Japanese industry is the “poka-yoke”. The poka-yoke method (meaning in Japanese: yokeru=prevent poka=mistake) is a method to prevent human errors using distractions and inattentiveness of the worker. The term “poh-kah yoh-ka” was implemented during the 60s by Shigeo Shingo, an industrial engineer in Toyota that is considered a pioneer in the field of “zero quality control”.

In almost all aspects of life, a human error might occur in one way or another. By implementing different types of signs and borders, a person can be directed to not only make no errors, but also perform only the correct actions. An example of the poka-yoke method in use is the RJ45 cable. It is designed to be inserted only one way.

RJ45 Cable

So why is this method so useful also when we have a group of highly trained workers that we trust to make no errors?

Firstly, using this method will enable new processes and new workers in the organization, work correctly already from their first time. (thus, decreasing expenses of mistakes and training)

Secondly, using this method fits perfectly with the continuous improvement culture which is a part of the “lean management” arsenal.

On top of that, using this method can drastically improve the quality and reliability of the product and of different procedures. By the very simple idea that there will not be any human errors to begin with and that all of the efforts can be focused on improving the organization and the product.

The poka-yoke has a few levels:

  1. Warning – prior instruction, signs, and documentation
  2. Disclosure – an indication of a correct / incorrect action
  3. Correction – correction after the error
  4. Prevention – automatic action or active indication before the error occurs (just like Mobileye)
  5. Immunity – where an error is impossible to occur (for example USB Type-C cable connects both sides)

In conclusion the poka-yoke method is one of the most important and influential work methods in the lean management sector. This method makes it possible to ensure a high-quality product while effectively reducing quality control costs.

Join us!

Subscribe to our newsletter and you will receive updates on various topics such as success stories, new developments, blog posts, fascinating podcast episodes and many other topics - directly to your email.