The Car Manufacturing Assemble Line

In a car manufacturing assembly line, there are four patterns or colors of technologies which have to plug into that specific color in the car making area. You can chain these stations together and there are rules. I don't see a real world cognate to it. That here's a paint and a tire and an engine part and maybe a seat belt or whatever that are all from different technologies but have to be part of the same assembly line. Do they all add up? I haven't really looked at that to see if there is a thematic connection.