Every methodology is imperfect until it is made perfect with the use of various tools and techniques. Achieving perfection is a never-ending process and by perfection we mean ‘zero defects.’ It is human behavior to make mistakes and in order to prevent those mistakes Shigeo Shingo adopted the poka-yoke technique in the Toyota Production System (TPS).
The term poka-yoke is a Japanese term, which means ‘mistake proofing.’ It is one of the helpful tools of Lean Six Sigma for continuous improvement.
Types of Poka-Yoke
The objective of adapting the poka-yoke technique is to eliminate any errors or mistakes, and to eradicate its recurrence once and for all.
This is a technique which warns users about the occurrence of an error and predicts the possibility of a defect. This mechanism is effective because of the implementation of a corrective action as soon as there is an error detection. And it doesn’t allow such errors to pass on to the next process.
A classic example of a poka-yoke device is electric sockets. The shape of the sockets is in such a manner that when we plug those in, it goes the right way. So, there is no question of making a mistake.
Having an error-free system is great and it has some additional benefits as well, such as:
- In Lean manufacturing, poka-yoke ensures reduction in the number of defects, which results in production of high quality items.
- Due to the reduction in the rate of errors, we see enhancement in the safety measures.
- There is improvement in the production process because of the non-value added element or waste removal.
- Poka-yoke devices are inexpensive and easy to implement.
- The ultimate advantage of installing these devices is customer satisfaction through quality and delivery performance.