Which of the following is an example of a poka-yoke device?

• A. A limit switch used to ensure that a hole is driven to the correct depth.
• B. An automatic storage and retrieval system.
• C. A numerical-control machine that reduces changeover time between products.
• D. A precision gauge used by quality inspectors to detect defects.

Answer: (A)

A limit switch used to ensure that a hole is driven to the correct depth exemplifies a poka-yoke device because it is specifically designed to prevent errors in the manufacturing process. Poka-yoke, a Japanese term meaning "mistake-proofing," refers to any mechanism in a lean manufacturing process that helps an equipment operator avoid (yokeru) mistakes (poka). In this context, the limit switch acts as a fail-safe to ensure that the operator cannot proceed unless the desired depth is reached, thus avoiding potential defects or damages associated with incorrect drilling.

This feature is particularly important in operations management, as it plays a crucial role in maintaining quality control and reducing rework or scrap costs by targeting root causes of errors at the source. By implementing such a device, organizations can enhance efficiency and ensure that products are made consistently to specifications, which is a core principle of effective operations management.