Question 1

A queuing model that follows the M/M/1 assumptions has λ = 10 and μ = 12.What is the average number of units in the system?

Accepted Answer

A) 0.83 
B) 2 
C) 2.5 
D) 5 
E) 6 
A) 0.83 
B) 2 
C) 2.5 
D) 5 
E) 6

Question 2

Which of the following is a requirement for application of Little's Law to be valid?

Accepted Answer

A) arrival rates that follow the Poisson distribution 
B) FIFO queue discipline 
C) steady state conditions 
D) single-server system 
E) multiphase system 
A) arrival rates that follow the Poisson distribution 
B) FIFO queue discipline 
C) steady state conditions 
D) single-server system 
E) multiphase system

Question 3

Which of the following is a measure of queue performance?

Accepted Answer

A) utilization factor for the system 
B) average queue length 
C) probability of a specific number of customers in the system 
D) average waiting time in the line 
E) all of the above 
A) utilization factor for the system 
B) average queue length 
C) probability of a specific number of customers in the system 
D) average waiting time in the line 
E) all of the above

Question 4

If the service time within a queuing system is constant,the service rate can be easily described by a negative exponential distribution.

Accepted Answer

A) True 
 B)False

Question 5

An M/M/1 model and an M/D/1 model each have an arrival rate of 1 per minute and a service rate of 3 per minute;the average queue length of the M/M/1 will be twice that of the M/D/1.

Accepted Answer

A) True 
 B)False

Question 6

A waiting-line system has three parts: the size of the arrival population,the behavior of arrivals,and the statistical distribution of arrivals.

Accepted Answer

A) True 
 B)False

Question 7

The study of waiting lines calculates the cost of providing good service but does not value the cost of customers' waiting time.

Accepted Answer

A) True 
 B)False

Question 8

A(n)________ queuing system has one waiting line,but several servers;a(n)________ queuing system is one in which the customer receives services from several stations before exiting the system

Accepted Answer

multiple-s

Question 9

A crew of mechanics at the Highway Department Garage repair vehicles that break down at an average of λ = 5 vehicles per day (approximately Poisson in nature).The mechanic crew can service an average of μ = 10 vehicles per day with a repair time distribution that approximates an exponential distribution.
a.What is the probability that the system is empty?
b.What is the probability that there is precisely one vehicle in the system?
c.What is the probability that there is more than one vehicle in the system?
d.What is the probability of 5 or more vehicles in the system?

Accepted Answer

(a)P0 = 1 - 5/10 = 0.50; (b)Pn > 1 = (5/

Question 10

Provide an example of a limited or finite population for a queue.

Accepted Answer

Answers will vary,but the text

Question 11

In queuing problems,the term "renege" refers to the fact that some customers leave the queue before service is completed.

Accepted Answer

A) True 
 B)False

Question 12

A single-phase waiting-line system meets the assumptions of constant service time or M/D/1.Units arrive at this system every 12 minutes on average.Service takes a constant 8 minutes.What is the average number in the system Ls in units?

Accepted Answer

A) 2.25 
B) 2.5 
C) 3.0 
D) 1.33 
E) 5.0 
A) 2.25 
B) 2.5 
C) 3.0 
D) 1.33 
E) 5.0

Question 13

Study of waiting-line models helps operations managers better understand:

Accepted Answer

A) service systems such as bank teller stations. 
B) maintenance activities that might repair broken machinery. 
C) shop-floor control activities. 
D) service systems such as amusement park rides. 
E) all of the above 
A) service systems such as bank teller stations. 
B) maintenance activities that might repair broken machinery. 
C) shop-floor control activities. 
D) service systems such as amusement park rides. 
E) all of the above

Question 14

A waiting-line system that meets the assumptions of M/M/1 has λ = 1,μ = 4.For this system,what is the probability of fewer than two units in the system?

Accepted Answer

A) 0.0625 
B) 0.25 
C) 0.75 
D) 0.9375 
E) 1.00 
A) 0.0625 
B) 0.25 
C) 0.75 
D) 0.9375 
E) 1.00

Question 15

In the finite population waiting line model,the average length of the queue is calculated from the probability the system is empty.

Accepted Answer

A) True 
 B)False

Question 16

Waiting-line models are useful to operations in such diverse settings as service systems,maintenance activities,and shop-floor control.

Accepted Answer

A) True 
 B)False

Question 17

In queuing problems,arrival rates are generally described by the normal probability distribution.

Accepted Answer

A) True 
 B)False

Question 18

Which of the following represents an unlimited queue?

Accepted Answer

A) drive-through lane at a fast-food restaurant 
B) small barbershop with only 5 chairs for waiting customers 
C) toll booth serving automobiles on an interstate 
D) faculty office with limited seating during office hours 
E) restaurant with no outside seating and limited capacity due to fire department restrictions 
A) drive-through lane at a fast-food restaurant 
B) small barbershop with only 5 chairs for waiting customers 
C) toll booth serving automobiles on an interstate 
D) faculty office with limited seating during office hours 
E) restaurant with no outside seating and limited capacity due to fire department restrictions

Question 19

The ________ of a waiting line and the probability that the queue is empty add to one.

Accepted Answer

The answer of The ________ of a waiting line and...

Question 20

A hospital emergency room always follows a FIFO queue discipline in the interest of fairness.

Accepted Answer

A) True 
 B)False

Exam 25: Waiting-Line Models

A queuing model that follows the M/M/1 assumptions has λ = 10 and μ = 12.What is the average number of units in the system?

Which of the following is a requirement for application of Little's Law to be valid?

Which of the following is a measure of queue performance?

If the service time within a queuing system is constant,the service rate can be easily described by a negative exponential distribution.

An M/M/1 model and an M/D/1 model each have an arrival rate of 1 per minute and a service rate of 3 per minute;the average queue length of the M/M/1 will be twice that of the M/D/1.

A waiting-line system has three parts: the size of the arrival population,the behavior of arrivals,and the statistical distribution of arrivals.

The study of waiting lines calculates the cost of providing good service but does not value the cost of customers' waiting time.

A(n)________ queuing system has one waiting line,but several servers;a(n)________ queuing system is one in which the customer receives services from several stations before exiting the system

Provide an example of a limited or finite population for a queue.

In queuing problems,the term "renege" refers to the fact that some customers leave the queue before service is completed.

A single-phase waiting-line system meets the assumptions of constant service time or M/D/1.Units arrive at this system every 12 minutes on average.Service takes a constant 8 minutes.What is the average number in the system Ls in units?

Study of waiting-line models helps operations managers better understand:

A waiting-line system that meets the assumptions of M/M/1 has λ = 1,μ = 4.For this system,what is the probability of fewer than two units in the system?

In the finite population waiting line model,the average length of the queue is calculated from the probability the system is empty.

Waiting-line models are useful to operations in such diverse settings as service systems,maintenance activities,and shop-floor control.

In queuing problems,arrival rates are generally described by the normal probability distribution.

Which of the following represents an unlimited queue?

The ________ of a waiting line and the probability that the queue is empty add to one.

A hospital emergency room always follows a FIFO queue discipline in the interest of fairness.

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A(n) queuing system has one waiting line,but several servers;a(n) queuing system is one in which the customer receives services from several stations before exiting the system