Poka Yoke

In this article we will discuss all about Poka Yoke. Poka Yoke is a method or tool for avoiding mistakes or error. You can imagine what will happen if there is no error or mistakes in this world !!!. Yes, that’s the importance of poka yoke.

We will be discussing about mistakes, principles of error, examples of poka yoke, importance of poka yoke, how to implement poka yoke and benefits of poka yoke.

Before we move further some words about mistake…

What is mistake or error

A mistake is an action or judgement which will adversely affect our objective or aim.

An example : Suppose we are going for a journey and in our journey we took a wrong way and we were 4 hours late to our destination. Here mistake is taking wrong way.

What will happen if we do a mistake

You can see in our example, we lost our precious enjoying time and fuel.

Hope you understood about mistakes.

Let’s see some examples related to manufacturing…

1. Processing error
2. Operation error
3. Missing parts
4. Missing information
5. False or wrong parts
6. Damaged Materials
7. Human Errors

All the above activities adversely affects:

1. Customers (Defects)
2. Employees (Injuries)

Which finally will results in waste or increase in cost

Now we are ready to discuss about poka yoke.

Let’s dive in…

What is Poka Yoke

Poka Yoke is the Japanese term, meaning: “mistake-proofing”

This term represents, methods or tools which avoid mistake or error

The main purpose of this tool is to prevent or eliminate the product defects by taking correct preventive measures.

Poka Yoke is also called as: Mistake proofing, Fail-safe, Idiot proofing, Fool-proofing

Principles of Poka Yoke

Mistake proofing or Poka yoke mainly focuses on following points…

1. Elimination: Eliminate the possibility of defects or errors by redesigning the product or process. Example: 1) Redesigning of mobile chargers i.e. from micro USB OTG chargers to new C cable chargers, which can be pugged to mobile in any of two ways instead of one way in micro usb otg chargers. If we try to plugin the micro usb otg in wrong way it may results in damage. 2) Also as an another example, if a welding process is causing error, eliminate the welding process by finding another solution for welding.
2. Replacement: Implementation of more reliable process or equipment to improve repeatability. Example: Use of automation instead of manual work
3. Prevention: Objective is to eliminate any chance of committing mistakes; To make sure things never go wrong. Example: 1) Electronic machines gets shutdown when overheating is observed with the help of sensors. 2) Some vehicles do not start when clutch is not engaged.
4. Facilitation: Actions taken or improvements done for making the work easy and mistake proof. Example: 1) Using visual controls like color coding and labelling to make work easier to perform 2) Using templates for fixing labels on a product.
5. Detection: An arrangement for detecting an error when it occurs and prevents further processing. Example: Use of sensors to detect any missing parts or incorrect assembly.
6. Mitigation: Mechanism that reduces the impact of errors or defects. Example: Electric fuse: When overloading is observed, fuse protects from over current as safety device

Examples of Poka Yoke