[gregmac]

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.