First American Bank is trying to find out whether it should install one or two drive-through teller windows. The following probability distributions for arrival intervals and service times have been developed from the historical data:
|
Time Between Arival
|
Probability
|
|
1
|
0.2
|
|
2
|
0.6
|
|
3
|
0.1
|
|
4
|
0.1
|
|
Service Time (In Min)
|
Probability
|
|
2
|
0.1
|
|
3
|
0.4
|
|
4
|
0.2
|
|
5
|
0.2
|
|
6
|
0.1
|
Suppose that in the two-server system, an arriving car will join the shorter queue. When the queues are of equal length, there's a 50-50 chance the driver will enter queue for either window.
a. Simulate both the one-and two-teller systems. Evaluate the average queue length, waiting time, and percentage utilization for each system.(using excel)
b. Describe your results in (a) and suggest the degree to which they could be employed to make a decision about which system to employ.