Mistake Proofing: Poka-Yoke

Mistake Proofing Poka-Yoke Achieving Perfection

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 a 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

Defect Detection

The objective of adapting the poka-yoke technique is to eliminate any errors or mistakes and to eradicate its recurrence once and for all.

Defect Prevention

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:

  1. In Lean manufacturing, poka-yoke ensures a reduction in the number of defects, which results in the production of high-quality items.
  2. Due to the reduction in the rate of errors, we see enhancement in the safety measures.
  3. There is an improvement in the production process because of the non-value added element or waste removal.
  4. Poka-yoke devices are inexpensive and easy to implement.
  5. The ultimate advantage of installing these devices is customer satisfaction through quality and delivery performance.