OSCM 373 EXAM 3 QUESTIONS AND ANSWERS
Why do we have queues?
A. It's polite to wait
B. So everybody gets a turn when a lot of people want to do the same thing at the same
time
C. People like queues
D. Some countries do not have queues - Answers -B. So everybody gets a turn when a
lot of people want to do the same thing at the same time
Customers arrive at a rate (λ) of 8 per hour (arrival pattern can be described with a
Poisson distribution with a mean of 8). Service representative requires an average of 6
minutes (1/μ) to assist a customer (service time can be described with an exponential
distribution with a mean of 6).
What is the average wait-time queue length?
A. 5.33
B. 48
C. 3.2
D. 4.8 - Answers -C. 3.2
Customers arrive at a rate (λ) of 8 per hour. Each service representative requires an
average of 6 minutes to assist a customer. The system has an average queue length of
4 customer.
What is the average Wait-Time?
A. 4/6 minute
B. 1/2 minute
C. 30 minutes
D. 24 minutes - Answers -C. 30 minutes
4/8=1/2 hour = 30 min
What effect an increase of Server-Utilization has on expected Wait-Time?
A. Expected wait would decrease
B. Expected wait time may increase if that's the result of increase arrival rate or
decrease if that the result of a decrease in service rate
C. Expected wait time would increase
D. Utilization has no effect on expected wait time - Answers -C. Expected wait time
would increase
What should be your goal when using John's Rule?
Why do we have queues?
A. It's polite to wait
B. So everybody gets a turn when a lot of people want to do the same thing at the same
time
C. People like queues
D. Some countries do not have queues - Answers -B. So everybody gets a turn when a
lot of people want to do the same thing at the same time
Customers arrive at a rate (λ) of 8 per hour (arrival pattern can be described with a
Poisson distribution with a mean of 8). Service representative requires an average of 6
minutes (1/μ) to assist a customer (service time can be described with an exponential
distribution with a mean of 6).
What is the average wait-time queue length?
A. 5.33
B. 48
C. 3.2
D. 4.8 - Answers -C. 3.2
Customers arrive at a rate (λ) of 8 per hour. Each service representative requires an
average of 6 minutes to assist a customer. The system has an average queue length of
4 customer.
What is the average Wait-Time?
A. 4/6 minute
B. 1/2 minute
C. 30 minutes
D. 24 minutes - Answers -C. 30 minutes
4/8=1/2 hour = 30 min
What effect an increase of Server-Utilization has on expected Wait-Time?
A. Expected wait would decrease
B. Expected wait time may increase if that's the result of increase arrival rate or
decrease if that the result of a decrease in service rate
C. Expected wait time would increase
D. Utilization has no effect on expected wait time - Answers -C. Expected wait time
would increase
What should be your goal when using John's Rule?
