Question 1

Which of the following is most likely to be served in a last-in, first-served (LIFS) queue discipline?
A) customers checking out at a grocery store
B) the in-basket on a manager's desk
C) patients entering a hospital emergency room
D) patrons waiting to be seated in a casual-dining restaurant
E) all of the above

Accepted Answer

The in-basket on a manager's desk is a typical example of a last-in, first-served (LIFS) queue discipline, as the most recently received documents or emails are often addressed first.

Question 2

A system in which the customer receives service from only one station and then exits the system is
A) a single-phase system
B) a single channel system
C) a multiple-channel system
D) a multiple-phase system
E) none of the above

Accepted Answer

A single-phase system refers to a service system where a customer goes through only one service station before exiting the system.

Question 3

A small hair styling salon has several operators. While customers do not have appointments, each is waiting to be served by a specific operator. This scenario provides an example of a
A) multiple-channel, multi-phase, limited queue length
B) single-channel, multi-phase, limited queue length
C) multi-channel, limited queue length
D) multiple single-channel systems, limited queue length
E) none of the above

Accepted Answer

This scenario is an example of multiple single-channel systems with a limited queue length because each operator acts as a single channel for service, and customers are waiting specifically for these operators, indicating a limitation in queue length for each operator.

Question 4

A university has only one technician in the repair station to care for the computers in the student labs. This system is most likely
A) a single channel, limited queue system
B) a single channel, limited population system
C) a multi-channel, limited queue system
D) a multi-channel, limited population system
E) none of the above

Accepted Answer

This system is a single channel, limited population system because there is only one technician (single channel) servicing a finite number of computers in the student labs (limited population).

Question 5

The sign at the bank that reads "Wait here for the first available teller" suggests the use of a __________ waiting line system.
A) dynamic-channel
B) random-channel
C) single channel
D) multi-channel
E) multiple line

Accepted Answer

The answer of The sign at the bank that reads...

Question 6

A waiting line meeting the assumptions of M/M/1 has average time between arrivals of 20 minutes and services items in an average of 10 minutes each; the utilization factor is approximately
A) 0.25
B) 0.33
C) 0.50
D) 0.67
E) 3.00

Accepted Answer

The answer of A waiting line meeting the assumptions of...

Question 7

Which one of the following is not a characteristic of a Model B or M/M/S system?
A) unlimited population size
B) single channel
C) single queue
D) single phase
E) Poisson arrival rate pattern

Accepted Answer

A Model B or M/M/S system typically involves multiple servers (S > 1), which contradicts the "single channel" characteristic. The other options are consistent with characteristics of the M/M/S queueing model.

Question 8

In a repetitive focus factory, the number of phases found in the system might refer to
A) the number of successive operations that have to be performed on a part
B) the number of machines doing the same necessary operations
C) the number of parts waiting to be processed
D) all of the above depending on the layout
E) none of the above

Accepted Answer

In a repetitive focus factory, the system is organized into a sequence of operations or phases that are necessary to produce a part. Therefore, the number of phases found in the system refers to the number of successive operations that have to be performed on a part. The other options (B and C) are related to the number of machines or parts waiting to be processed, which may vary depending on the specific layout of the factory, but they do not necessarily indicate the number of phases in the system.

Question 9

A waiting line model meeting the assumptions of M/M/1 has an arrival rate of 2 per hour and a service rate of 6 per hour; the utilization factor for the system is approximately
A) 0.25
B) 0.33
C) 0.50
D) 0.67
E) 3.00

Accepted Answer

The utilization factor ($ρ$) in an M/M/1 queue is calculated as the arrival rate ($λ$) divided by the service rate ($μ$), i.e., $ρ = λ/μ$. Given $λ = 2$ per hour and $μ = 6$ per hour, $ρ = 2/6 = 0.33$.

Question 10

Which one of the following is not a characteristic of a Model C or M/D/1 system?
A) single channel
B) single phase
C) Poisson arrival rate pattern
D) exponential service time pattern
E) unlimited population size

Accepted Answer

In a M/D/1 queueing system, the "M" stands for Markovian (Poisson arrival process), "D" for deterministic service times (not exponential), and "1" for a single server. Therefore, an exponential service time pattern is not a characteristic of M/D/1 systems.

Question 11

"Women and children first!" declares the captain of a sinking ship. His directive employs which of the following queue disciplines in disembarking passengers?
A) priority
B) random
C) FIFO or FIFS
D) LIFO or LIFS
E) SPT

Accepted Answer

The captain's directive of "Women and children first!" is prioritizing certain passengers to disembark before others, therefore the answer is priority.

Question 12

Which of the following is not a measure of a queue's performance?
A) average time spent in queue
B) average queue length
C) probability that service facility will be idle
D) utilization
E) All of the above are performance measures.

Accepted Answer

All the options listed (average time spent in queue, average queue length, probability that service facility will be idle, and utilization) are indeed measures of a queue's performance. These metrics help in analyzing and optimizing queue management systems.

Question 13

A university has several technicians in the repair station to care for the computers in the student labs. This system is most likely
A) single channel, limited queue system
B) single channel, limited population system
C) multi-channel, limited queue system
D) multi-channel, limited population system
E) none of the above

Accepted Answer

The answer of A university has several technicians in the...

Question 14

Which one of the following is not a characteristic of a Model A or M/M/1 system?
A) exponential service time pattern
B) single number of channels
C) single number of phases
D) Poisson arrival rate pattern
E) limited population size

Accepted Answer

A Model A or M/M/1 system assumes an infinite population size, so Option E (limited population size) is not a characteristic of this type of system.

Question 15

In a repetitive focus factory, the number of channels available for the processing of a certain part would likely refer to
A) the number of successive operations that have to be performed on that part
B) the number of machines doing the same necessary operations
C) the number of parts waiting to be processed
D) all of the above depending on the layout
E) none of the above

Accepted Answer

In a repetitive focus factory, each machine or workstation is focused on performing a specific operation repeatedly. Therefore, the number of channels available for processing a certain part would refer to the number of machines doing the same necessary operations.

Question 16

In the basic queuing model (M/M/1), arrival rates are distributed by
A) continuous probability distributions
B) normal probability distributions
C) negative exponential probability distributions
D) Poisson distributions
E) lognormal distributions

Accepted Answer

The answer of In the basic queuing model (M/M/1), arrival...

Question 17

A large discount store and supermarket has a hair styling salon on its premises. The salon has several operators. Salon customers can shop in other parts of the store until their name is called for salon service, at which time the customer will be served by the next available stylist. This scenario provides an example of a
A) multi-channel, limited queue length
B) single-channel, multi-phase, limited queue length
C) multi-channel, unlimited queue length
D) multiple single-channel systems, limited queue length
E) single-channel, unlimited queue length

Accepted Answer

The salon operates with multiple stylists (channels) who can serve customers simultaneously, and customers can wait (queue) without a specified limit, making it a multi-channel, unlimited queue length system.

Question 18

Which of the following is a measure of queue performance?
A) utilization factor
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

Accepted Answer

All of the given options are measures of queue performance. Utilization factor and average queue length depict how efficiently servers are being utilized and how long customers must wait in line, respectively. Probability of a specific number of customers in the system helps in balancing the server's availability and service quality. The average waiting time in the line provides information about customer service quality, where a longer waiting time indicates poor service. Therefore, all measures are needed to assess queue performance accurately.

Question 19

As the average service rate μ increases, the shape of the negative exponential distribution of service times
A) grows steadily steeper without limit
B) has an ever steeper slope that eventually turns positive
C) becomes less gently curved as it moves ever closer to the graph origin
D) takes on a more uniform slope over a wide range of service times
E) changes in appearance from convex to concave

Accepted Answer

As the average service rate μ increases, the mean service time decreases and the spread of service times decreases as well. This results in the negative exponential distribution becoming less gently curved and moving closer to the origin. However, the shape of the distribution remains exponential, and it does not take on a uniform slope or switch from convex to concave.

Question 20

In the basic queuing model (M/M/1), service times are described by
A) binomial probability distributions
B) negative exponential probability distributions
C) Poisson probability distributions
D) normal probability distributions
E) lognormal distributions

Accepted Answer

In the M/M/1 queuing model, service times follow a negative exponential probability distribution. This is because the inter-arrival times of customers are assumed to follow a Poisson process, and the service times are assumed to be memoryless, meaning that the likelihood of the service time being completed is the same at any point during the service. Both of these assumptions lead to a negative exponential distribution for service times.

Quiz 21: The Modi and Vam Methods of Solving Transportation Problems

Which of the following is most likely to be served in a last-in, first-served (LIFS) queue discipline?

A system in which the customer receives service from only one station and then exits the system is

A small hair styling salon has several operators. While customers do not have appointments, each is waiting to be served by a specific operator. This scenario provides an example of a

A university has only one technician in the repair station to care for the computers in the student labs. This system is most likely

The sign at the bank that reads "Wait here for the first available teller" suggests the use of a __________ waiting line system.

A waiting line meeting the assumptions of M/M/1 has average time between arrivals of 20 minutes and services items in an average of 10 minutes each; the utilization factor is approximately

Which one of the following is not a characteristic of a Model B or M/M/S system?

In a repetitive focus factory, the number of phases found in the system might refer to

A waiting line model meeting the assumptions of M/M/1 has an arrival rate of 2 per hour and a service rate of 6 per hour; the utilization factor for the system is approximately

Which one of the following is not a characteristic of a Model C or M/D/1 system?

"Women and children first!" declares the captain of a sinking ship. His directive employs which of the following queue disciplines in disembarking passengers?

Which of the following is not a measure of a queue's performance?

A university has several technicians in the repair station to care for the computers in the student labs. This system is most likely

Which one of the following is not a characteristic of a Model A or M/M/1 system?

In a repetitive focus factory, the number of channels available for the processing of a certain part would likely refer to

In the basic queuing model (M/M/1) , arrival rates are distributed by

Which of the following is a measure of queue performance?

As the average service rate μ increases, the shape of the negative exponential distribution of service times

In the basic queuing model (M/M/1) , service times are described by