Process, not product
First thing: my actual experience with manufacturing is limited. However, I can still draw conclusions. And my take on things, after watching some selected videos, is that Henry Ford would feel right at home with the magic of the assembly line. From tiny to magestic, the process requires that you start with the simple pieces, and from there you go to your goal. Remember, process, not product.
Today, I sat through what seemed to take a long time. Turning a van into a van. Seriously. I was following a video blog through a modern factory where vans arrived from the assembly line, elsewhere. Then, with due care and attention, some very particular pieces are refabbed, creating the fininshed travel van. Not magic, exactly. Rather, attention to details, and a learned ability to tell stitching shades aoart on a menu of custom chairs.
I’m skipping details. The factory also turned pieces of selected lumber into cabinets. That might be the magic, actually. At any point, a selected chassis (think naked truck) will be routed to the right department, where a team of trained eyes will post-fit the pieces that make a home out of a shell.
My own experience (in assembly work) was one where axles were given the necessary mix of bearings and brakes. Still a process, not a product. We also had designated departments, and specialists in process. I know (now) how much grease is required in a bearing cup. I learned the skill from a master. And no the correct answer is “more”. It works with grease, and other things. Not salt, though.