Be Fault-Proof With Poka-Yoke

Poka-Yoke is a Japanese term that means ” fault-proof ”. In other words, the design of the product is designed to prevent the user from making mistakes and causing damage. A good example is a sink. There is a hole at the upper limit of it, in case the user would forget to turn off the tap. The faucet handle is also very simple to understand: it is lifted to increase the flow of water and it is lowered to reduce and stop it.


At the manufacturing level, the idea is to design the processes, the equipment and the tools so that the operations cannot be executed incorrectly. 

How to identify potential errors? 

Poka-Yoke has no magic procedures to apply to its processes so t

hat they become error-proof. However, there are several concepts to be adopted to ensure that potential errors are identified before the product is considered defective. First, it is important to have a multidisciplinary team that will assess all possible concerns. Subsequently, it is a question of identifying the sources of errors and classifying them in these categories: 

  • The required action is not executed or is executed incorrectly.
  • An undesirable action is performed.
  • The essential information to perform the action is misinterpreted.
  • The action is not performed correctly because of the complexity.

Next, use one of the techniques below to ensure that the error is 100% detected: 

  • Use preventive devices such as jigs, anti-fouling systems, proximity sensors, warning lights, alarms, etc.
  • Modify the design to ensure that the assemblingofthe parts can only be done in one way. 

These techniques should be an integral part of the process and be visible to the operator for alerting. Of course, the inspections during the process and the final inspection remain essential.