A branch office of a large engineering firm has one on-line terminal connected to a central computer system for 16 hours each day. Engineers, who work throughout the city, drive to the branch office to use the terminal for making routine calculations. The arrival pattern of engineers is random (Poisson) with an average of 20 persons per day using the terminal. The distribution of time spent by an engineer at the terminal is exponential with an average time of 30 minutes. Thus the terminal is 5/8 utilized (20 x 1/2 = 10 hours out of 16 hours available). The branch manager receives complaints from the staff about the length of time many of them have to wait to use the terminal. It does not seem reasonable to the manager to procure another terminal when the present one is only used five-eighths of the time, on the average. How can queueing theory help this manager?