2.5 hours to build a Model Y from start to finish. And it's not over yet.
The Tesla Giga Shanghai Model Y line was recently featured in an exclusive walkthrough from China's Xinhua News Agency.
The process is further being adapted for each step to be automated. The role of humans will eventually be to supervise robots.
There's an awful lot of human labor going on in that video. Not that it can't be automated, but some aspects are surprisingly hard to automate. I'm also slightly curious whether that 2.5 hours is from when the chassis parts start being welded together, or after the chassis blank hits the final assembly line.
Henry Ford got the build time of the Model T to 93 minutes.
Obligatory maritime reference: the fastest Liberty ship (440' x 57', 14,000 long tons GVW) build was 4 days, 15 hours, and change from keel laying to launch. That was a stunt--most of the ships took around 30-50 days depending on steel supplies.
There's a lot of really interesting tradeoffs in industrial process design between making subassemblies larger and more complex and doing more of that work in final assembly. At least in my industry, it's one of those cases where in theory it's better to do as much as possible in the subassembly stage, but there are sometimes places where the theory isn't the same as practice. One really important example is that the welding has to be completely done before painting begins* or you end up putting yourself further behind with paint touchup. I'm sure that's even more so with automotive paint. I assume from the build time that the panels are all finished beforehand.
* This isn't 100% true but if you're still welding while painting, you have a lot to think about in terms of clearances between good paint and weld and the like.