Error proof in the plastic mold design

Murphy's Law: if one thing has a bad possibility, no matter how small the possibility, it will always happen.

In the mold design, if the insert does not have error proof, several assembly method can be installed, perhaps cause the mold damaged or wrong product after molding.

For example, the upper picture show the logo. if the logo is made of insert, the insert could be installed with 2 methods, then the insert could be molded with wrong way, to cause money lose. So it's very import to design error proof for inserts to install.