A multiple-server system has customers arriving at an average rate of five per hour and an average service time of forty minutes.The minimum number of servers for this system to have a utilization factor under 1 is:
A)2.
B)3.
C)4.
D)5.
E)None of the above.
Customers arrive at a suburban ticket outlet at the rate of 14 per hour on Monday mornings (exponential interarrival times).Selling the tickets and providing general information takes an average of 3 minutes per customer,and varies exponentially.There is 1 ticket agent on duty on Mondays.

Question

Quizplus · Accepted Answer

The service rate per server is 1.5 customers per hour (60/40). To keep utilization under 1, the arrival rate (5) divided by the total service rate (number of servers * 1.5) must be less than 1. Therefore, at least 4 servers are needed (5/6 < 1).

A Multiple-Server System Has Customers Arriving at an Average Rate