Poka-Yoke in English means a mistake-proofing system. This method helps employees to avoid mistakes during production. This system ensures safety production without errors, taking off the pressure of employees to not doing something wrong. Safety is the most important factor in our lives, more than that, Poka-Yoke methodology, offers the opportunity to work protected, and also to use items in everyday life, they are not harmful to us.
The picture below represents a toy for kids, which is a good example of this principle. Every yellow shape fits in just one hole, so it’s just one way to put all the shapes in this plastic ball.

Let’s see some examples of everyday life:
The USB cable and the plugs ensure, they can be, just in a certain way connected. Households, for example, like microwave, washing machine, dishwasher, for safety, they are not working, until the door is open.
Another common example of Poka-Yoke thinking comes right from the office:

In production, this principle can be applied in various ways.
An important fact to remember! Prevent errors from appearing, NOT correcting after appearing!!!!
In manufacturing, a mistake-proofing system can be achieved by using holding devices and fixtures. These exclude the possibility to do a movement, operation in a wrong way.

This device on this image above is fixing and blocking the plastic part from moving, ensuring the right position for assembling. The metal dowel pin prevents the plastic part, from incorrect fixing, with the connector on the right side. A white arrow on the bottom of the holding device, pointing on the right, shows the correct position on the assembly line. The assembly line begins from the left to the right side, for this reason, is the arrow pointed on the right.
On the next image, is represented the plugging system for an electric-checking station, with multiple heads serving different products. At the moment the product is changed on the production line, the head is replaced with another one, this one containing the plugging cables too. Some of the heads have 2 cables, as you can see on the image, and some of them have 3 cables. It’s very easy to replace the head by matching the colors.

In production preventing errors or assuring, the operator respects all the required steps, this issue is resolved, by using sensors with green and yellow light (or red).
In this way, the operator can’t skip any step in assembling.