Consider a continuous operation in which raw beans arrive to a processing unit. The beans arrive at an average steady rate of 114 tons per hour for the first 10 hours of each day and then stop. The beans are then processed by the processing unit, which, when operating, can process at a steady state of 60 tons/hr. If need be, the processing unit can process for 24 hours a day. If beans arrive when the processing unit is busy a queue of inventory will form.

How many hours a day does the processing unit operate?