Right now the trend in manufacturing is the lights-out factory - everything done by machines.
In 2009 I picked up a load of beer from Anheuser-Buschs Baldwinsville, NY, brewery. After they loaded my trailer I had to go into Shipping for my paperwork. In this massive room they had rack upon rack of beer on pallets, automated forklifts, and one person who had two jobs: prepare shipping documents and fix any machine that broke down. The beer distributors would send their orders to St. Louis via Electronic Data Interchange. A-Bs mainframe would go through it and decide how many of their 10 breweries would take the order - because this company makes so many products every brewery has a different product mix. You might get part of it from Baldwinsville, part from Newark, NJ, part from St. Louis
Okay, so you need product from Baldwinsville. This facility gets EDI from STL. Their computer creates a pick list and sends it to a forklift, which pulls the order and loads it on the trailer. These machines dont even need human help to charge - when their batteries get low enough they back into a charging bay and right into the connector.
I took a look at this and asked the shipper if the Teamsters Union (the Teamsters are the Union controlling this plant) was okay with this. The Teamsters set this up. They were able to move their people into higher-paying jobs inside the brewery with this system.
Totally automated factories are what well get if they come back to the US. Rather than having hundreds or thousands of workers screwing little screws into iPhones, youll have rows of ABB or FANUC robots doing it and one or two people with toolboxes in case one of them stops working.