
Jidoka ◾ 127
How to Improve Human Reliability
We already discussed standardized work, visual management, and 5S as
ways to improve human reliability. There is another method.
Poka-Yoke
Poka means inadvertent error, and yoke means prevention. Poka-yoke means
implementing simple low-cost devices that either detect abnormal situations
before they occur, or once they occur, stop the line to prevent defects.
4
Shingo
was careful to distinguish between errors, which he felt were impossible to
avoid, and defects, which he believed could be entirely eliminated.
5,6
Common Errors
Poka-yokes reduce a worker’s physical and mental burden by eliminating the