What is the meaning of Poka Yoke?
Poka Yoke
is a manufacturing concept that entails controlling human error as much as possible so that products are finished correctly the first time, and don’t need any extra work. Implementing Poka Yoke in manufacturing saves you time and money, since you won’t need to repair or recall items, and it leads to higher-quality products. A Poka Yoke checklist walks you through applying these principles to your manufacturing.
What should be in a Poka Yoke checklist?
A Poka Yoke device is anything that stops defects from appearing in your product. The specific measure taken to achieve this will depend on what errors are commonly made or have been reported by consumers. A second goal of Poka Yoke systems is to make sure the end product cannot be accidentally broken due to misuse.
As such, any Poka Yoke checklist should include:
- The underlying problem you are trying to fix
- What is causing the problem or error to continue recurring
- If the error can easily be prevented
- If it is preventable, how you can prevent it
- Which Poka Yoke method is most appropriate for the situation
- What will be triggered if a worker makes the error (such as a warning light, a buzzer, or the machine stopping)
- If the end product can only be used one way now that the error has been fixed
What are the different Poka Yoke methods?
Since Poka Yoke systems and mechanisms are heavily dependent on what exactly is going wrong, there are different Poka Yoke methods out there that are appropriate in different contexts. Sometimes, you’ll be able to prevent errors through Poka Yoke devices; other times, the most you can do is warn that an error has been made. Regardless, there are three methods of using Poka Yoke in manufacturing.
Contact method
The contact method of Poka Yoke involves using a product’s size, shape, color, or another physical trait to check for errors. It is so named because these devices govern how you make contact with the product, for example by only allowing you to insert screws one way.
Constant number method
A Poka Yoke system that uses the constant number method is designed to make sure that a certain action or actions is performed the correct number of times. If not, the worker will be alerted. It could be something as simple as making sure a screw was tightened the right amount.
Sequence method
Sequential Poka Yoke devices are essentially quality control checklists. A sequential Poka Yoke is something that ensures all necessary steps in a production process have been completed before the next phase starts, and one way to make sure of this is by requiring workers to complete tasks on a checklist.
What kinds of errors does Poka Yoke fix?
Poka Yoke is focused on eliminating human error across a variety of manufacturing contexts. To that end, it can help you address several different common errors, including:
- Processing errors: error as a result of not following processes correctly
- Setup errors: using the wrong tools or machine settings
- Missing or incorrect part errors: Poka Yoke systems are a valuable way of ensuring no components are missing or used incorrectly
- Operation errors: performing a specific operation incorrectly
- Measurement errors: adjusting equipment, performing a test, or measuring dimensions incorrectly
What are some Poka Yoke examples?
Depending on the industry, a Poka Yoke system could look different, but the core idea is always the same – to reduce instances of human error wherever possible. Some Poka Yoke examples during the manufacturing process include:
- Barriers that maintain the correct distance between workers and equipment
- Pins that prevent connecting parts from being inserted more than one way
- Weight sensors that can detect when a part is missing
- Color-coded wiring that prevents mistakes in assembly
- Lights that flash when an error is detected
The idea of mistake-proofing is also present in finished products. The meaning of Poka Yoke is reflected in:
- Washing machines that won’t start until the door has been shut
- USB drives that can only be inserted one way to prevent damage to devices
- Automated cash registers that count change exactly
Why should you use a Poka Yoke checklist?
High-quality products are only one way Poka Yoke can help your business. Given enough time, a Poka Yoke system will:
- Reduce time spent training your employees to avoid errors
- Keep your workers and customers safe by reducing errors
- Save you money on quality checks and product adjustments
- Reduce waste and get you the most from your raw materials
- Improve customer satisfaction and brand image
A Poka Yoke checklist can help you make sure you have solutions in mind to deal with whatever errors you have observed in production. Lumiform’s template helps you work through the steps of Poka Yoke and decide on appropriate systems to use in order to mitigate human error.
