The bank manager of a busy downtown location found herself unable to find good teller help so she invested in an ATM to handle the routine withdrawals that tended to occupy an inordinate amount of the teller's time. Before she installed the ATM she found that customers were arriving on average every 2 minutes (Poisson distributed)and it took a teller 30 seconds (exponentially distributed)to process their request. The ATM is able to maintain a constant 30 second service time. What is the impact on system utilization?
A)There is no change.
B)Utilization has dropped by 15%.
C)Utilization has dropped by 30%.
D)Utilization has dropped by 45%.

Question

Quizplus · Accepted Answer

The system utilization remains the same because the average arrival rate and the service rate have not changed with the introduction of the ATM. The ATM processes customers at the same rate as the teller did, every 30 seconds.

The Bank Manager of a Busy Downtown Location Found Herself