Recently I came in contact with a die of a part. In which Pokayoke was used. The concept used to develop the die was as follows:

Pokayoke is practiced in industries so that any person can not do a mistake even if he wants to do it intentionaly or else by mistake.

Pokayoke is a japanese word which means mistake proofing. It was coined by Shigeo Shingo as a part of toyota production system.

The part is designed in such a way that it fits only if its correctly inserted.

You will get clear idea about pokayoke with some of the examples:

Pokayoke Applied on USB Cable:
You must have seen the USB cable or pendrive when you insert it in laptop or computer then it gets inserted only in one way.

USB Cable

Pokayoke Applied on Sim Card

The other fine live example would be the sim card that you are using in your smartphones.

It is given a slant chamfer at its one end. So it would compulsarily fix in right position only.

Sim Card