A night shift is just what it sounds like. It is the second (or third) shift at a facility after the normal day shift ends.
A night shift usually exists for one of two reasons. In production environments, a night shift adds capacity. This is very useful for production requiring large amounts of space or excessive capital.
In service environments, you may find a capacity-related night shift, but service work doesn’t keep well. People don’t want their burger cooked at 12:04 am and they don’t want their phone call returned at 11:14 pm.
More commonly, service groups use the night shift to match customer needs—24 hour access to phone support, or overnight dry cleaning.
This teamwork is especially important in Lean. Continuous improvement requires standardization, so both day and night teams have to be going in the same direction.
That can be tricky when they never get to speak to each other in ‘real time’. Most communication is done via email and phone messages. It requires sophisticated team building techniques to prevent an ‘us-against-them’ attitude between the day shift and the night shift.