Poka Yoke is a Lean Manufacturing tool that allows us to detect possible errors in the production process, prevent them and thus avoid defects in manufactured parts. Poka Yoke is usually translated as “mistake-proofing” or “inadvertent error prevention” and comes from the Japanese terms: Poka = unforeseen errors, and Yokeru = avoid.
Origin | Error and Defect | Benefits | How It Works | How to Implement | Application | Poka Yoke & M-Box
Pokayoke originated in the Toyota factory in the 1960s, when Shigeo Shingo developed them as a quality assurance tool. For Shigeo Shingo, most errors are human and from these are generated defects in the manufactured parts, so he highlighted the introduction of mechanisms and elements of error detection proactively, and thus avoid defects.
To understand Pokayoke, it is necessary to know the difference between error and defect.
The defect occurs when any feature of the product goes out of specification and results in its rejection.
The error is any mistake or failure committed in the execution of an activity during the productive process that could generate a defect.
Therefore, the error is the cause of the defect.
To implement Poka yoke it is necessary, in principle, to classify the quality characteristics of the product and identify all the types of defects that can be generated. Then it will be fundamental to analyze all the information related to the defects, the statistics of each of them together with the statistics of stops and machine failures will help us to know them (origin, frequency and corrective actions).
Then, it will be necessary to perform an AMEF or Cause Effect Diagram to find the root cause of the defect. Subsequently, each step of the operation where the defect occurs is analyzed, at this time we will identify the Poka yoke opportunities.
Then, we will identify the stages of the process where the deviation has occurred. Later, we design the Poka yoke to later implement it, and finally, follow-up and improvements.
Poka yoke has different applications, from productive, service, administrative process to the improvement in the usability of a product by the user. In this order of ideas there are different types of Poka yoke, depending on the situation to be improved, among them:
Having real floor data, is essential to develop a successful Pokayoke. This information will allow us to know the defects that occur in each production process and act consistently against them.
Finally, having a reliable production monitoring system such as M-Box will provide us with the necessary data to develop a successful Pokayoke and at the same time measure their impact in favor of eliminating defects in our production line.
