A quick little background on “poka-yoke.” Also written by others as “pokayoke” or “poka yoke,” it all refers to error-proofing or mistake-proofing.
And what do those terms mean? Why, making it impossible to perform an operation incorrectly!
Mistake-proofing suggests implementing countermeasures to not only prevent but also eliminate the chance of someone completing a process or operation other than the way it was prescribed. Anytime you can prevent errors from occurring means you are preventing the need to rework or fix those errors. You can complete the operation one way only, and that one way is the proper or correct way.
The picture suggests two applications of poka-yoke. The left side is a children’s toy – you can put the blocks through the table in one way and one way only.
Same with the right side of the photo, which is the back of a computer. Computer technology is probably the most commonly-identified opportunity for error-prevention and poka-yoke because there are so many different types of cables and adapters that correlate with different components and applications. There’s only one place to plug in an ethernet cable, and just one acceptable plug orientation. There are multiple locations to attach a USB cable, but the plug must also be oriented in the proper fashion. Same thing with serial ports, HDMI cables, and the like.
And where we still use older non-error-proofed technology we have at least utilized colors on RCA stereo cables and inputs/outputs so we can plug the right cables into the right locations.
This article at Velaction provides a few more examples of everyday applications of poka-yoke. It’s more common than you might think.