My impression was that the extra hours are due to the factories being on a 24/7 uninterrupted production cycle. Having people work 12 hour shifts instead of 8 reduces the headcount required by 33%.
I don't think shift duration changes the headcount, it really depends on the total hours per week each person is working.
There's 168 hours in a week. If people work for 40 hours a week, to cover the 168 hours you need to employ 4.2 people for every employee you want on the floor at any given time. That means everyone works 5 8-hour shifts, or 3.3 12-hour shifts per week.
If you reduce headcount by 33%, that works out to 2.8 people per employee on the floor, which means everyone works 60 hours per week -- 7.5 8-hour shifts, or 5 12-hour shifts. That's a lot.
Not true, you can pay 33% or more and still save money on overhead, head count, and shift changes. You see this in the US despite overtime laws, where it is still better to pay a worker 150% for the extra hours.
There's 168 hours in a week. If people work for 40 hours a week, to cover the 168 hours you need to employ 4.2 people for every employee you want on the floor at any given time. That means everyone works 5 8-hour shifts, or 3.3 12-hour shifts per week.
If you reduce headcount by 33%, that works out to 2.8 people per employee on the floor, which means everyone works 60 hours per week -- 7.5 8-hour shifts, or 5 12-hour shifts. That's a lot.