What is Poka Yoke – A Definitive Guide

What is the Meaning of Poka Yoke?

Poka yoke meaning is: Mistake Proofing.

It is a methodology that helps the operators to avoid mistakes to happen.

Initially, it was known as idiot proofing or baka-yoke.

Mr. Shigeo Shingo changed the name from Baka to Poka to
avoid employees to be offended.

The basic idea is that a product (or process) has to be designed
in a way that makes impossible to assembly (or perform the process) in a wrong way.

Do you remember the 7 wastes?

This methodology is a way to reduce the 7 wastes.

In particular, I am thinking about Defects and Overprocessing.

And you?

If you want to go into details of the difference between Poka Yoke and Baka Yoke,
I suggest you read this article on Re-Translating Lean from its origin.

Poka Yoke vs Baka Yoke

Mr. Jun Nakamuro in his article clarifies that:

There are two types of people on the shop floor:

  1. People that do not pay full attention and make errors.
  2. People that have not the ability to prevent errors … so they make it!

The first type of people is “Poka” category.
The second type of people is “Baka” category

In the Toyota Production System, it is clearly stated that the “Poka” type is the worst people a company can have.

They are actively disengaged.


the mistake-proofing can be implemented by specific training.

On the other hand, Baka-Yoke can be implemented with Jigs, Sensors, Mechanical or Electrical Improvements.

Poka Yoke Training


A simple way to train a classroom is suggested by Mr. Roser in his article.

The main idea is to use surprises from Kinder Suprise Eggs from Ferrero.

Here there is the article on Poka-Yoke Training

Poka Yoke Examples

Keeping in mind that there is a difference between Poka and Baka but into
the reality, people use only Poka.

Here I want to collect examples of poka yoke to help you to understand.

Mechanical Help

How to design a tool that prevents the operators to create defects.

An advanced level of Error Proofing

When the electronic help is designed to reduce defects at the source.

Application in a transactional field

The state of Ohio is implementing Lean to reduce defects from forms and papers.


  • Poka Yoke in lean is a mistake-proofing methodology.
  • You have not to be focused only on the process but on the people and training, too.
  • The electronics can be used but you have to be balanced between costs and benefits.
  • Can be used into the “transactional world”