What Is Mistake Proofing (Poka-Yoke)

Mistake proofing is defined as an improvement technology that uses a device or procedure, also called apoka-yoke, to prevent defects or equipment malfunction during operation ofequipment or processes.

Mistake-proofing devices are important as they enforce correct operations by eliminating choices that lead to incorrect actions,signal or stop a process if an error is made or a defect created, and prevent machine and product damage.

Mistake-proofing activities can be integrated with the lean tools of Quick-Changeover, 5S-visual-management, One-Piece-Flow, and Standard-Work. The possibilities for mistake-proofing areendless and typically involve very little investment in resources.

By applying mistake-proofing (poka-yoke) you will :

• Promotes individual responsibility for qualityownership.
• Poka-yokes are analogous to 100% inspection, but withlittle investment.
• Detect and eliminate defects as early in the process aspossible.
• Provides immediate feedback, thus reducing the time forcorrective action.
• Establishes a system of successive checks for eachoperation.
• Provides for self-check activities, which gives quickerfeedback than successive checks.
• Ensures that proper conditions exist prior to actualproduction, and prevents mistakes from occurring in the first place.
• Focuses on elimination of causes for errors rather thanjust identification.
• Enhances customer satisfaction through the eliminationof defects.
• Focuses on waste reduction in defects and processing.
• Improves first-pass yield.