What is a poka-yoke in maintenance? Provide an example.

• A. A training program that teaches workers to avoid mistakes.
• B. A device that prevents human error by design; e.g., a plug that only fits the correct connector.
• C. A periodic audit of maintenance procedures.
• D. A checklist used at the end of a shift.

Answer: (B)

Poka-yoke is about building safeguards into equipment or work steps so mistakes can’t happen or are caught immediately. In maintenance this means designing tools, interfaces, or processes so the wrong action cannot be performed. A classic example is a plug that only fits the correct connector—the shape or keying prevents connecting parts in the wrong way, avoiding mis-wiring or improper assembly.

This shows error-proofing by design, which is the core idea of poka-yoke. Other options describe training, audits, or checklists—which help reduce mistakes but don’t prevent the error from occurring through the design itself.