Question 1

A queueing system is said to be in a "steady state" when customers arrive at a constant rate,that is,without any variability.

Accepted Answer

A) True 
 B)False

Question 2

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:

Accepted Answer

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. 
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 3

Figure
Refer to the following data for a multiple-server,nonpreemptive priority queueing model:  
-What is the average time in line (in minutes)for a high priority item?

Accepted Answer

A) 2. 
B) 5. 
C) 24. 
D) 35. 
E) 54. 
A) 2. 
B) 5. 
C) 24. 
D) 35. 
E) 54.

Question 4

The assumption of constant service times cannot be used with human servers because of the inevitable variability.

Accepted Answer

A) True 
 B)False

Question 5

A system has one service facility that can service 10 customers per hour.The customers arrive at an average rate of 6 per hour.In this case,no waiting line will form.

Accepted Answer

A) True 
 B)False

Question 6

The lack-of-memory property refers to a customer's willingness to wait in line even though there are other customers that will be served first.

Accepted Answer

A) True 
 B)False

Question 7

If there are 4 servers,what is the average time it takes in minutes to rent a videotape?

Accepted Answer

A) 2. 
B) 3. 
C) 4. 
D) 5. 
E) 6. 
A) 2. 
B) 3. 
C) 4. 
D) 5. 
E) 6.

Question 8

In a preemptive priority system,the lowest-priority customer being served is ejected back into the queue whenever a higher-priority customer enters the queueing system.

Accepted Answer

A) True 
 B)False

Question 9

As the ratio of arrival rate to service rate is increased,which of the following is likely?

Accepted Answer

A) Customers move through the system in less time because utilization is increased. 
B) Customers move through the system more slowly because utilization is increased. 
C) Utilization is decreased because of the added strain on the system. 
D) The average number in the system decreases. 
E) None of the above. 
A) Customers move through the system in less time because utilization is increased. 
B) Customers move through the system more slowly because utilization is increased. 
C) Utilization is decreased because of the added strain on the system. 
D) The average number in the system decreases. 
E) None of the above.

Question 10

Figure
Refer to the following data for a multiple-server,nonpreemptive priority queueing model:  
-What is the overall arrival rate per hour?

Accepted Answer

A) 3. 
B) 4. 
C) 5. 
D) 8. 
E) 15. 
A) 3. 
B) 4. 
C) 5. 
D) 8. 
E) 15.

Question 11

Figure
Refer to the following data for a multiple-server,nonpreemptive priority queueing model:  
-What is the average number of all items waiting in line for service?

Accepted Answer

A) 0. 
B) 0.24. 
C) 1.74. 
D) 1.98. 
E) 2.22. 
A) 0. 
B) 0.24. 
C) 1.74. 
D) 1.98. 
E) 2.22.

Question 12

In a single-server system,the utilization factor is equal to the mean arrival rate divided by the mean service rate.

Accepted Answer

A) True 
 B)False

Question 13

A single bay car wash with an exponential arrival rate and service time has cars arriving an average of 10 minutes apart,and an average service time of 4 minutes.The utilization factor is:

Accepted Answer

A) 0.24. 
B) 0.4. 
C) 0.67. 
D) 2.5 
E) None of the above. 
A) 0.24. 
B) 0.4. 
C) 0.67. 
D) 2.5 
E) None of the above.

Question 14

A multiple priority queueing model assumes that:

Accepted Answer

A) arrival rates are exponentially distributed. 
B) service rate is exponentially distributed. 
C) items are serviced in the order of arrival. 
D) items are serviced in order of priority class. 
E) service activities are preemptive. 
A) arrival rates are exponentially distributed. 
B) service rate is exponentially distributed. 
C) items are serviced in the order of arrival. 
D) items are serviced in order of priority class. 
E) service activities are preemptive.

Question 15

Which of the following is not an example of a commercial service system?

Accepted Answer

A) ATM cash machine. 
B) Brokerage service. 
C) Travel agency. 
D) Tool crib. 
E) Call center. 
A) ATM cash machine. 
B) Brokerage service. 
C) Travel agency. 
D) Tool crib. 
E) Call center.

Question 16

On average,how many parties of truckers are waiting to be seated?

Accepted Answer

A) 0.27. 
B) 0.52. 
C) 0.88. 
D) 1.36. 
E) 1.75. 
A) 0.27. 
B) 0.52. 
C) 0.88. 
D) 1.36. 
E) 1.75.

Question 17

The most commonly used queueing models assume a service rate that is exponential.

Accepted Answer

A) True 
 B)False

Question 18

What is the average number of customers in the system with 8 servers?

Accepted Answer

A) 2. 
B) 3. 
C) 4. 
D) 5. 
E) 6. 
A) 2. 
B) 3. 
C) 4. 
D) 5. 
E) 6.

Question 19

If clerk cost is $30 per hour and customer waiting time represents a cost of $20 per hour,how many clerks can be justified on a cost basis?

Accepted Answer

A) 2. 
B) 3. 
C) 4. 
D) 5. 
E) 6.
Customers filter into a record shop at an average of 1 per minute (exponential interarrivals)where the service rate is 15 per hour (exponential service times). 
A) 2. 
B) 3. 
C) 4. 
D) 5. 
E) 6.
Customers filter into a record shop at an average of 1 per minute (exponential interarrivals)where the service rate is 15 per hour (exponential service times).

Question 20

What is the minimum number of servers needed to achieve an average time in the system of less than three minutes?

Accepted Answer

A) 2. 
B) 3. 
C) 4. 
D) 5. 
E) 6. 
A) 2. 
B) 3. 
C) 4. 
D) 5. 
E) 6.

Exam 12: Queueing Models

A queueing system is said to be in a "steady state" when customers arrive at a constant rate,that is,without any variability.

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:

Figure Refer to the following data for a multiple-server,nonpreemptive priority queueing model: -What is the average time in line (in minutes)for a high priority item?

The assumption of constant service times cannot be used with human servers because of the inevitable variability.

A system has one service facility that can service 10 customers per hour.The customers arrive at an average rate of 6 per hour.In this case,no waiting line will form.

The lack-of-memory property refers to a customer's willingness to wait in line even though there are other customers that will be served first.

If there are 4 servers,what is the average time it takes in minutes to rent a videotape?

In a preemptive priority system,the lowest-priority customer being served is ejected back into the queue whenever a higher-priority customer enters the queueing system.

As the ratio of arrival rate to service rate is increased,which of the following is likely?

Figure Refer to the following data for a multiple-server,nonpreemptive priority queueing model: -What is the overall arrival rate per hour?

Figure Refer to the following data for a multiple-server,nonpreemptive priority queueing model: -What is the average number of all items waiting in line for service?

In a single-server system,the utilization factor is equal to the mean arrival rate divided by the mean service rate.

A single bay car wash with an exponential arrival rate and service time has cars arriving an average of 10 minutes apart,and an average service time of 4 minutes.The utilization factor is:

A multiple priority queueing model assumes that:

Which of the following is not an example of a commercial service system?

On average,how many parties of truckers are waiting to be seated?

The most commonly used queueing models assume a service rate that is exponential.

What is the average number of customers in the system with 8 servers?

If clerk cost is $30 per hour and customer waiting time represents a cost of $20 per hour,how many clerks can be justified on a cost basis?

What is the minimum number of servers needed to achieve an average time in the system of less than three minutes?

Introduction

Linear Programming: Basic Concepts

Linear Programming: Formulation and Applications

The Art of Modeling With Spreadsheets

What-If Analysis for Linear Programming

Network Optimization Problems

Using Binary Integer Programming to Deal With Yes-Or-No Decisions

Nonlinear Programming

Decision Analysis

Cd Supplement - Decision Analysis

Forecasting

CD Supplement - Additional Queueing Models

Computer Simulation: Basic Concepts

CD Supplement - the Inverse Transformation Method for Generating Random Observations

Computer Simulation With Crystal Ball

CD - Solution Concepts for Linear Programming

CD - Transportation and Assignment Problems

CD - Pertcpm Models for Project Management

CD - Goal Programming

CD - Inventory Management With Known Demand

CD - Inventory Management With Uncertain Demand

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