Corrected entry: There are two plot holes in the factory that Matt Damon works in, where they build droids. There are very sophisticated droids throughout the movie performing several different tasks. So why is he working there where his job is to stamp sheet metal, attach it with bolts, and then move the droids to the oven? Surely a droid would be capable of this work, and with the factory's high level of production they would likely be able to afford a generic one for those menial tasks. Also, what is the purpose of the giant oven that irradiates everything inside? It can't be to temper or treat the metal of the droids, because then you have radioactive robots, which also means this can't be a way of charging up their batteries/ power plant. Plus they're assembled by this time, so it's irradiating the wires, hydraulics, and circuitry as well.