Six Sigma Green Belt Certification Practice Exam

Which lean concept refers to mistake-proofing a process?

1. Poka-yoke

2. Pull

3. Queue time

4. Process flow chart

The correct answer is: Poka-yoke

The term that refers to mistake-proofing a process is Poka-yoke. This lean concept is designed to prevent errors from occurring by incorporating safeguards, triggers, or automatic corrections within a process to ensure that defects are eliminated or reduced in quality. The primary goal of Poka-yoke is to create mechanisms that make it nearly impossible for a worker to make a mistake, or to instantly highlight when a mistake has occurred. Poka-yoke is paramount in quality management as it encourages the design of processes that are robust enough to minimize human error, thus enhancing overall efficiency and product reliability. Implementing Poka-yoke techniques promotes a culture of continuous improvement, where the focus is on creating systems that are inherently less prone to errors. In contrast, while concepts such as Pull relate to inventory management and production flow, Queue time pertains to the waiting periods within processes and may indirectly impact efficiency, neither directly addresses the prevention of errors in the same way Poka-yoke does. A Process flow chart serves as a diagnostic tool that maps out the steps in a process but does not specifically incorporate measures to prevent mistakes.