A poka-yoke is any mechanism in a process that helps an equipment operator avoid (yokeru) mistakes (poka) and defects by preventing, correcting, or drawing attention to human errors as they occur.
[4] Poka-yoke is derived from poka o yokeru (ポカを避ける), a term in shogi that means avoiding an unthinkably bad move.
More broadly, the term can refer to any behavior-shaping constraint designed into a process to prevent incorrect operation by the user.
The requirement of a depressed brake pedal to shift most of the cars with an automatic transmission from "Park" to any other gear is yet another example of a poka-yoke application.
Forcing functions are very effective in safety critical situations such as this, but can cause confusion in more complex systems that do not inform the user of the error that has been made.
[7] The term poka-yoke was applied by Shigeo Shingo in the 1960s to industrial processes designed to prevent human errors.
The aim of poka-yoke is to design the process so that mistakes can be detected and corrected immediately, eliminating defects at the source.
[2] Shingo argued that errors are inevitable in any manufacturing process, but that if appropriate poka-yokes are implemented, then mistakes can be caught quickly and prevented from resulting in defects.