Although "Quality should be produced, not controlled", few productions make this dream come true. Manual visual quality control is thus one of the most responsible operations in production.
Today's state of the art, where you can connect several cameras to all cameras for viewing from all sides, you can apply neutron networks and laser scanners, you can help a precision robot manipulate the camera over the product or the product in front of the cameras. ppm ”as a much more realistic matter.