I would suspect that the assemblers are going through training right now and that workflow processes are being refined. If they are making oneses-twosies in Lafayette then they probably have fitted and re-fitted the same components a half-dozen times while the process engineers are modifying programming for the robotics to position assemblies.
It is probably being done with their engineers, designers and the most senior, lead assemblers. If you think about all of the steps that are required to fall in place for each workstation they are literally making hundreds of production process adjustments a day. These are not big things that will change how a car rolls off the line but subtle things like how many mm to move the dashboard up to the firewall before the screw guns zap it in to place.
And in that, you have just described the whole Japanese philosophy on car building - Kaizen. Continuous small improvements.
You're close to right on how things are done at SIA. But there are only so many robots that can be used - that's where Tesla messed up and had to shut their plant down again this week for a bit. They've tried to automate things there too much. Back in 1989, when the plant opened, we had 1,300 employees. Now there are about 5,600, with the Ascent line added. It's also a case of, they don't have to reinvent the wheel each and every time a new model or body style change is done. There's are teams in body, paint, and trim that have been working for the past year on figuring out work stations, parts deliveries, parts locations, and just how and what each person working the line will do.
Now they're in the tweaking phase, where they'll figure out that at full production speeds, it's better to have this box of screws in this location for ease of grabbing instead of that location, or the forklift operator will deliver the box of parts here instead of there. Been there, done that, seen it many times. In case it's not been clear on this forum, I'm probably the only person in the country that sells Subaru's that also worked at the factory in Indiana building them. So I've seen model change-over, new model start-up, and all this stuff before. Stamping has to figure things out, they have to make sure the warehouse is laid out for storage, make sure the dies for the transfer presses are set up, body has to make sure all the robots and welders are right, paint has to make sure all the robots and carriers are right (I remember how big the carriers were before, it'll be interesting to see if they can still use the same ones with the Ascent), and trim has to make sure that when the painted body hits the south side of the floor that by the time it gets to the north side, turned around, and then back to the south side that a finished car is fueled up and ready to go.
It IS a huge process - but they've got 30 years of experience doing it.
