Question 1

The cost of customer waiting is easy to estimate.

Accepted Answer

A) True 
 B)False

Question 2

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.
What is the system utilization?

Accepted Answer

A)  0.6 
B)  0.7 
C)  0.8 
D)  0.9 
E)  1 
A)  0.6 
B)  0.7 
C)  0.8 
D)  0.9 
E)  1

Question 3

A firm has two separate phone systems for customers to use when contacting the firm. A manager is considering combining the two systems into a single system (with the same number of total servers as the two existing systems). What is likely to be the result of this change?
I. The new system will have higher utilization of servers.
II. The new system will have longer wait times for customers.
III. The new system will have shorter wait times for customers.

Accepted Answer

A)  I only. 
B)  II only. 
C)  III only. 
D)  I and II only. 
E)  II and III only. 
A)  I only. 
B)  II only. 
C)  III only. 
D)  I and II only. 
E)  II and III only.

Question 4

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 answer choices is correct. 
A)  0.24. 
B)  0.4. 
C)  0.67. 
D)  2.5 
E)  None of the answer choices is correct.

Question 5

Queueing models enable finding an appropriate balance between the cost of service and the amount of waiting.

Accepted Answer

A) True 
 B)False

Question 6

A small popular restaurant at an interstate truck stop provides priority service to truckers. The restaurant has ten tables where customers may be seated. The service time averages 40 minutes once a party is seated. The customer arrival rate is 12 parties per hour, with the parties being equally divided between truckers and non-truckers.
On average, how much longer in minutes do parties of non-truckers spend in the system, compared to parties of truckers?

Accepted Answer

A)  4. 
B)  7. 
C)  11. 
D)  15. 
E)  It is impossible to determine without more information. 
A)  4. 
B)  7. 
C)  11. 
D)  15. 
E)  It is impossible to determine without more information.

Question 7

A loading dock with two servers who work together as a team would be an example of a multiple-server system.

Accepted Answer

A) True 
 B)False

Question 8

A small popular restaurant at an interstate truck stop provides priority service to truckers. The restaurant has ten tables where customers may be seated. The service time averages 40 minutes once a party is seated. The customer arrival rate is 12 parties per hour, with the parties being equally divided between truckers and non-truckers.
What is the approximate average time in minutes that truckers wait to be seated?

Accepted Answer

A)  2.7 
B)  4.5 
C)  8.4 
D)  13.6 
E)  15.8 
A)  2.7 
B)  4.5 
C)  8.4 
D)  13.6 
E)  15.8

Question 9

Most queueing models assume that the form of the probability distribution of interarrival times is an exponential distribution.

Accepted Answer

A) True 
 B)False

Question 10

A small popular restaurant at an interstate truck stop provides priority service to truckers. The restaurant has ten tables where customers may be seated. The service time averages 40 minutes once a party is seated. The customer arrival rate is 12 parties per hour, with the parties being equally divided between truckers and non-truckers.
What is the approximate average time in minutes that non-truckers wait to be seated?

Accepted Answer

A)  2.7 
B)  4.5 
C)  8.4 
D)  13.6 
E)  15.8 
A)  2.7 
B)  4.5 
C)  8.4 
D)  13.6 
E)  15.8

Question 11

The standard deviation for the degenerative distribution equals zero.

Accepted Answer

A) True 
 B)False

Question 12

$\begin{array}{l}
\begin{array}{|l|l|}
\hline \text { Priority }&\text { Average Arrival Rate (exponential interarrival times) }\
\hline \text { High } & 3 \text { per hour } \
\hline \text { Low } & 5 \text { per hour } \
\hline
\end{array}
\end{array}$
$\begin{array}{|l|l|}
\hline Nurrber~ of~ servers:&5\
\hline Service~ rate:&2~ per~ hour ~(exponential ~service~ times)\
\hline 
\end{array}$
What is the average time in line (in minutes) for a low 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 13

A multiple-server queueing system with an exponential arrival rate and service time has a mean arrival rate of 4 customers per hour and a mean service time of 18 minutes per customer. The minimum number of servers required to keep the utilization factor under 1 is:

Accepted Answer

A)  1. 
B)  2. 
C)  3. 
D)  4. 
E)  5. 
A)  1. 
B)  2. 
C)  3. 
D)  4. 
E)  5.

Question 14

Customers arrive at a video rental desk at the rate of one per minute (exponential interarrival times). Each server can handle 0.4 customers per minute (exponential service times).
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

Question 15

Choosing the number of servers in a system involves finding an appropriate trade-off between the cost of the servers and the amount of waiting.

Accepted Answer

A) True 
 B)False

Question 16

For a system that has a high utilization factor, decreasing the service rate will have only a negligible effect on customer waiting time.

Accepted Answer

A) True 
 B)False

Question 17

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

Accepted Answer

A) True 
 B)False

Question 18

The only distribution of interarrival times that fits having random arrivals is the exponential distribution.

Accepted Answer

A) True 
 B)False

Question 19

$\begin{array}{l}
\begin{array}{|l|l|}
\hline \text { Priority }&\text { Average Arrival Rate (exponential interarrival times) }\
\hline \text { High } & 3 \text { per hour } \
\hline \text { Low } & 5 \text { per hour } \
\hline
\end{array}
\end{array}$
$\begin{array}{|l|l|}
\hline Nurrber~ of~ servers:&5\
\hline Service~ rate:&2~ per~ hour ~(exponential ~service~ times)\
\hline 
\end{array}$
What is the average number of high priority 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 20

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 answer choices is correct. 
A)  2. 
B)  3. 
C)  4. 
D)  5. 
E)  None of the answer choices is correct.

The cost of customer waiting is easy to estimate.

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:

Queueing models enable finding an appropriate balance between the cost of service and the amount of waiting.

A loading dock with two servers who work together as a team would be an example of a multiple-server system.

Most queueing models assume that the form of the probability distribution of interarrival times is an exponential distribution.

The standard deviation for the degenerative distribution equals zero.

A multiple-server queueing system with an exponential arrival rate and service time has a mean arrival rate of 4 customers per hour and a mean service time of 18 minutes per customer. The minimum number of servers required to keep the utilization factor under 1 is:

Customers arrive at a video rental desk at the rate of one per minute (exponential interarrival times). Each server can handle 0.4 customers per minute (exponential service times). What is the minimum number of servers needed to achieve an average time in the system of less than three minutes?

Choosing the number of servers in a system involves finding an appropriate trade-off between the cost of the servers and the amount of waiting.

For a system that has a high utilization factor, decreasing the service rate will have only a negligible effect on customer waiting time.

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

The only distribution of interarrival times that fits having random arrivals is the exponential distribution.

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:

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

Forecasting

Computer Simulation: Basic Concepts

Computer Simulation With Analytic Solver

Filters

Exam 11: Queueing Models

The cost of customer waiting is easy to estimate.

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:

Queueing models enable finding an appropriate balance between the cost of service and the amount of waiting.

A loading dock with two servers who work together as a team would be an example of a multiple-server system.

Most queueing models assume that the form of the probability distribution of interarrival times is an exponential distribution.

The standard deviation for the degenerative distribution equals zero.

A multiple-server queueing system with an exponential arrival rate and service time has a mean arrival rate of 4 customers per hour and a mean service time of 18 minutes per customer. The minimum number of servers required to keep the utilization factor under 1 is:

Customers arrive at a video rental desk at the rate of one per minute (exponential interarrival times). Each server can handle 0.4 customers per minute (exponential service times). What is the minimum number of servers needed to achieve an average time in the system of less than three minutes?

Choosing the number of servers in a system involves finding an appropriate trade-off between the cost of the servers and the amount of waiting.

For a system that has a high utilization factor, decreasing the service rate will have only a negligible effect on customer waiting time.

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

The only distribution of interarrival times that fits having random arrivals is the exponential distribution.

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:

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

Forecasting

Computer Simulation: Basic Concepts

Computer Simulation With Analytic Solver

Filters