I toured a Deere plant in Waterloo, Iowa this summer.
Before the 90 minute tour, there was a film, which included some footage of a Deere assembly line in the early 1950's.
Man, the workers had to hustle to keep up, as assemblies moved down the line.
At the plant I toured this summer, the $1,000,000 tractors moved between assembly stations on robot sleds, after the workers keyed in their stage of work was complete. Assembly looked leisurely, in contrast to the film, but of course experienced professionals often make complex tasks look easy.