Why Fail Safe When You Can Poka-yoke?

Poka-Yoke is a Japanese word for "fail-safing" that I just came across and suspect might be entering my UI vocabulary soon. The entry from Wikipedia:

Poka-yoke (IPA: [poka joke]) is a Japanese term that means "fail-safing", "Foolproof" or "mistake-proofing" — avoiding (yokeru) inadvertent errors (poka)) is a behavior-shaping constraint, or a method of preventing errors by putting limits on how an operation can be performed in order to force the correct completion of the operation. The concept was formalised, and the term adopted, by Shigeo Shingo as part of the Toyota Production System. Originally described as Baka-yoke, but as this means "fool-proofing" (or "idiot proofing") the name was changed to the milder Poka-yoke.

An example includes 3.5" floppy disk. The top-right corner is shaped in a certain way so that the disk cannot be inserted upside-down. In the manufacturing world an example might be that the jig for holding pieces for processing only allows pieces to be held in one orientation, or has switches on the jig to detect whether a hole has been previously cut or not, or it might count the number of spot welds created to ensure that, say, four have been executed by the operator.