Regardless of the multiple technical issues, there is also the base presumption that every customer is trying to cheat the store on every transaction. So every

Regardless of the multiple technical issues, there is also the base presumption that every customer is trying to cheat the store on every transaction. So every item you scan has to be placed on the giant scale that is the bagging area, and remain there until your entire order is processed. So the usage pattern goes: scan, bag, scan, bag, scan, stop and wait for employee, scan, bag, enter code, weigh, bag, scan, stop and wait for employee, scan, bag, process payment, move all bags, leave. You can't scan the bread and eggs and the watermelon and leave the fragile crushable items on the belt until the heavy items are already in the bag. Everything must be moved immediately to the bagging area, human! So if you don't plan your scanning, you end up moving some things twice. Weight discrepancy noted. Return items to the bagging area and wait for the store employee to verify that you aren't cheating! For the regular checkouts, the usage pattern is often customer moves entire order to first conveyor belt, employee 1 scans all items and passes them onto the second conveyor belt. At this point, there may be an employee 2 that bags the scanned items and places the bags back into the empty cart as employee 1 processes payment, then both bag until the order is processed. That works fine. Not great, but it works well enough. At some stores, the bagger employee has been deprecated. The cashier bags items into a bag carousel. At some stores, the conveyors are not used. Cashier scans items directly from the cart. The most efficient stores, such as Aldi (Aldi Sud, in US), scan directly from one cart into another, and don't even bother with bags. The customer can keep Tyvek bags in their vehicle, and bag directly from the cart to their trunk, if they even care about bags at all. (Maybe they keep specialized containers for specific sizes of cans, instead?) Self-checkout doesn't work like that. It's almost designed to be annoying and frustrating. It could be so much better if they only designed the experience from the ground up instead of trying to make a drop-in replacement for the employee checkout lanes, which were designed for different criteria decades ago.