Ford Motor Company Model T rolling out of a factory as it comes of an early assembly line on Earth
An assembly line was a type of manufacturing set up in which laborers or robots assembled goods by repeating the same tasks over and over in a set order.
In 2153, Travis Mayweather and Trip Tucker marveled over the identical appearances of three Delphic Expanse spheres, the former suggesting it was as though they were made on an assembly line. (ENT: "Chosen Realm")
In 2268, after Leonard McCoy reminded James T. Kirk that Richard Daystrom's first 4 multitronic computers weren't big successes, Kirk explained that genius didn't work like an assembly line. (TOS: "The Ultimate Computer")