The entire procedure is automated. People are needed merely to take the luggage to the airplane.
Before leaving on holiday by plane, I always have my fingers crossed hoping that luggage will follow me to the destination. I believe there is nothing worse than starting your vacation with such an inconvenience. First, doing the paperwork for lost luggage, then a quick shopping trip to buy the basics required on holiday.
Have you ever asked yourself what "machinery" brings luggage to the right plane? Did you think people shift suitcases from one cart or belt to another? Somewhere perhaps, but the video posted on YouTube shows a slightly different picture. Some suitcases are indeed shifted by people, but most of the procedure is automated and also includes robots.
You can see more about it in the footage below taken at the Amsterdam airport, which shows an intertwined system of paths that luggage must travel to arrive at the right plane. Considering the complexity of the way, there is little luggage lost, don't you think?