Deck 19: Waiting Line Models

Question 1

Which of the following is not considered to be an element of a waiting line system?

A) the customer population source
B) the service system
C) the average number of customers waiting in line
D) the arrival and service patterns
E) the priorities used for controlling the line

Answer 1

C

Question 2

Which of the following is not considered to be an element of a waiting line system?

A) the customer population source
B) the service system
C) the average number of customers in the system
D) the arrival and service patterns
E) the priorities used for controlling the line

Answer 2

C

Question 3

One challenge in designing waiting lines is to obtain service systems with _______ but not ______ amounts of capacity.

A) adequate, excessive
B) adequate, expensive
C) low cost, cheap
D) justifiable, noticeable
E) infinite, excessive

Answer 3

A

Question 4

A single-line, multiple-server system has _____ ______ in terms of waiting times than the same system with a line for each server.

A) poorer performance
B) similar performance
C) better performance
D) comparable performance
E) reduced performance

Question 5

A customer population is called _______________ when the number of potential new customers is affected by the number of customers already in the system.

A) finite
B) infinite
C) dependent
D) independent
E) biased

Question 6

What occurs when a customer enters a waiting line but decides to exit before being served?

A) balking
B) walking
C) reneging
D) vacillating
E) jockeying

Question 7

Which of the following is least likely to be considered a finite customer population?

A) subassemblies in a just-in-time manufacturing environment
B) fast food restaurant employees waiting to use the restroom
C) planes waiting to take off at an airport
D) a class of 10 students who might visit their professor during office hours
E) cars taking Exit 76 off of a freeway during rush hour

Question 8

Which of the following is least likely to be considered a finite customer population?

A) subassemblies in a just-in-time manufacturing environment
B) fast food restaurant employees waiting to use the restroom
C) planes waiting to take off at an airport
D) customers in a grocery store
E) a class of 10 students who might visit their professor during office hours

Question 9

Which of the following is least likely to be considered an infinite customer population?

A) subassemblies in a just-in-time manufacturing environment
B) customers in an amusement park
C) a class of 500 students who might visit their professor during office hours
D) customers in a grocery store
E) cars taking Exit 76 off of a freeway during rush hour

Question 10

Which of the following is least likely to be considered a finite customer population?

A) subassemblies in a just-in-time manufacturing environment
B) customers in an amusement park
C) fast food restaurant employees waiting to use the restroom
D) planes waiting to take off at an airport
E) a class of 10 students who might visit their professor during office hours

Question 11

Which of the following is not considered to be an element of a waiting line system?

A) the customer population source
B) the service system
C) the arrival and service patterns
D) the priorities used for controlling the line
E) the system utilization rate

Question 12

Which of the following is least likely to be considered an infinite customer population?

A) customers in an amusement park
B) a class of 500 students who might visit their professor during office hours
C) customers in a grocery store
D) planes waiting to take off at an airport
E) cars taking Exit 76 off of a freeway during rush hour

Question 13

Which of the following is least likely to be considered a finite customer population?

A) subassemblies in a just-in-time manufacturing environment
B) fast food restaurant employees waiting to use the restroom
C) a class of 500 students who might visit their professor during office hours
D) planes waiting to take off at an airport
E) a class of 10 students who might visit their professor during office hours

Question 14

Which of the following is least likely to be considered an infinite customer population?

A) customers in an amusement park
B) a class of 500 students who might visit their professor during office hours
C) a class of 10 students who might visit their professor during office hours
D) customers in a grocery store
E) cars taking Exit 76 off of a freeway during rush hour

Question 15

A customer population is called _______________ when the number of potential new customers is not affected by the number of customers already in the system.

A) finite
B) infinite
C) dependent
D) independent
E) unbiased

Question 16

What occurs when a customer decides not to enter the waiting line?

A) vacillating
B) walking
C) reneging
D) balking
E) jockeying

Question 17

Which of the following is not considered to be an element of a waiting line system?

A) the priorities used for controlling the line
B) the customer population source
C) the service system
D) the arrival and service patterns
E) the average amount of time customers spend waiting

Question 18

What occurs when a customer enters one line and then switches to a different line in an effort to reduce his or her waiting time?

A) balking
B) walking
C) reneging
D) vacillating
E) jockeying

Question 19

Which of the following is not considered to be an element of a waiting line system?

A) the customer population source
B) the service system
C) the arrival and service patterns
D) the average amount of time a customer spends in the system
E) the priorities used for controlling the line

Question 20

Which of the following is least likely to be considered an infinite customer population?

A) customers in an amusement park
B) a class of 500 students who might visit their professor during office hours
C) customers in a grocery store
D) cars taking Exit 76 off of a freeway during rush hour
E) fast food restaurant employees waiting to use the restroom

Question 21

Customers generally consider which of the following priority rules to be the fairest?

A) quickest service requirements first
B) longest service requirements first
C) first-come, first-served
D) best customers first
E) highest profit customer first

Question 22

Which of the following waiting line systems best describes a bank with a single waiting line that feeds customers to multiple identical servers?

A) single-server, single-phase
B) single-server, multi-phase
C) multi-server, single-line, single-phase
D) multi-server, multi-line, single-phase
E) multi-server, multi-phase

Question 23

Which of the following waiting line systems best describes a drive-through car wash?

A) single-server, single-phase
B) single-server, multi-phase
C) multi-server, single-line, single-phase
D) multi-server, multi-line, single-phase
E) multi-server, multi-phase

Question 24

Which of the following is not considered to be a valid performance measure of a waiting line system?

A) the average number of customers waiting in line
B) the average number of customers in the system
C) the average amount of time customers spend waiting
D) the arrival pattern
E) the system utilization rate

Question 25

Waiting line models typically assume that service times are represented by what distribution?

A) Poisson
B) normal
C) Weibull
D) exponential
E) hypergeometric

Question 26

If only two cars can physically fit between the ordering and pay window of a fast-food drive-through, the waiting line system has a ____ _____ waiting line.

A) constrained server
B) finite size
C) infinite size
D) multi-phase
E) single service

Question 27

A short waiting line may result from all of the following except:

A) constant customer arrivals
B) excess capacity
C) exceptional server efficiency
D) demand surges
E) a properly designed system

Question 28

System server capacity is a function of ______ and _______.

A) phase, lines
B) time, lighting
C) facilities, management
D) facilities, proficiency
E) utilization, proficiency

Question 29

In waiting line terminology, what is another name for server?

A) clerk
B) channel
C) host
D) concierge
E) provider

Question 30

Which of the following is not considered to be a valid performance measure of a waiting line system?

A) the average number of customers waiting in line
B) the average number of customers in the system
C) the service system
D) the average amount of time customers spend waiting
E) the system utilization rate

Question 31

Waiting line models typically assume that customer arrival rates are represented by what distribution?

A) Poisson
B) Gaussian
C) Weibull
D) Cauchy
E) exponential

Question 32

Which of the following is not one of the characteristics that define a service system?

A) the number of customers
B) the number of waiting lines
C) the number of servers
D) the arrival and service patterns
E) the service priority rules

Question 33

For which of the following priority rules are the customers waiting times most likely to be proportional to their respective service times?

A) first come, first served
B) longest service requirements first
C) quickest service requirements first
D) best customers first
E) emergencies first

Question 34

Which of the following waiting line systems best describes a grocery store, where each register has its own line and server?

A) single-server, single-phase
B) single-server, multi-phase
C) multi-server, single-line, single-phase
D) multi-server, multi-line, single-phase
E) multi-server, multi-phase

Question 35

Which of the following waiting line systems best describes a men's clothing store, where one of the sales clerks first assists the customer in selecting the material and style and then one of the tailors measures the customer to ensure a custom-fitted suit?

A) single-server, single-phase
B) multi-server, multi-phase
C) multi-server, single-line, single-phase
D) multi-server, multi-line, single-phase
E) single-server, multi-phase

Question 36

Which of the following is not considered to be a valid performance measure of a waiting line system?

A) the average number of customers waiting in line
B) the customer population source
C) the average number of customers in the system
D) the average amount of time customers spend waiting
E) the system utilization rate

Question 37

In a well designed waiting line system it is the variability in _____ and ______ patterns that causes waiting lines.

A) server, customer
B) poisson, exponential
C) arrival, service
D) arrival, poisson
E) service, exponential

Question 38

Which of the following waiting line systems best describes a drive-through service at a fast-food restaurant, where the order is placed at the first service point, the order is paid for at the second service point, and the food is picked up at the third service point?

A) single-server, single-phase
B) single-server, multi-phase
C) multi-server, single-line, single-phase
D) multi-server, multi-line, single-phase
E) multi-server, multi-phase

Question 39

Services require a single activity or a series of activities and are identified by what term?

A) round
B) step
C) phase
D) activity set
E) facet

Question 40

When calculating waiting line metrics you must ensure that the arrival rate and service rate are:

A) for the same day.
B) for the same probability.
C) for the same site.
D) for the same time period.
E) for the same utilization factor.

Question 41

For a single-server, single-line, single-phase waiting line system, where $\lambda$ represents the mean arrival rate of customers and $\mu$ represents the mean service rate, what is the formula for the average time spent in the system?

A) $\lambda$ / $\mu$
B) $\lambda$ / ( $\mu$ - $\lambda$ )
C) $\lambda$ ² / $\mu$ ( $\mu$ - $\lambda$ )
D) 1 / ( $\mu$ - $\lambda$ )
E) $\lambda$ / $\mu$ ( $\mu$ - $\lambda$ )

Question 42

Which of the following is not considered to be a valid performance measure of a waiting line system?

A) the average number of customers waiting in line
B) the average number of customers in the system
C) the average amount of time customers spend waiting
D) the system utilization rate
E) the service pattern

Question 43

Which of the following is not an assumption of the waiting line models presented in the textbook?

A) the customers are patient
B) customers come from an infinite population
C) customer arrival rate is described by a Poisson distribution
D) service times are described by an exponential distribution
E) the waiting line priority rule is quickest service requirements first

Question 44

Which of the following is not an assumption of the waiting line models presented in the textbook?

A) the customers are patient
B) customers come from an infinite population
C) customer arrival rate is described by a Poisson distribution
D) service times are described by a Normal distribution
E) the waiting line priority rule is first-come, first-served

Question 45

Which of the following is not an assumption of the waiting line models presented in the textbook?

A) the customers are patient
B) customers come from an infinite population
C) customer arrival rate is described by a Poisson distribution
D) service times are described by an exponential distribution
E) in a multi-phase system, a server can serve more than one customer at a time

Question 46

4! = _________?

A) 0
B) 1
C) undefined
D) 4
E) 24

Question 47

Which of the following is not an assumption of the waiting line models presented in the textbook?

A) the customers are patient
B) customers come from a finite population
C) customer arrival rate is described by a Poisson distribution
D) service times are described by an exponential distribution
E) the waiting line priority rule is first-come, first-served

Question 48

0! = _________?

A) 0
B) 1
C) undefined
D) -1
E) (II)

Question 49

Which of the following is not an assumption of the waiting line models presented in the textbook?

A) balking is not allowed
B) reneging is allowed
C) jockeying is not allowed
D) customer arrival rate is described by a Poisson distribution
E) service times are described by an exponential distribution

Question 50

Which of the following is not an assumption of the waiting line models presented in the textbook?

A) balking is allowed
B) reneging is not allowed
C) jockeying is not allowed
D) customer arrival rate is described by a Poisson distribution
E) service times are described by an exponential distribution

Question 51

The average time customers spend waiting and the average time a customer spends in the system:

A) are the same metric.
B) use the same formula.
C) are not considered.
D) are different system metrics.
E) only apply to multi-server systems.

Question 52

Which of the following is not an assumption of the waiting line models presented in the textbook?

A) the customers are patient
B) customers come from an infinite population
C) customer arrival rate is described by a Gaussian distribution
D) service times are described by an exponential distribution
E) the waiting line priority rule is first-come, first-served

Question 53

For a single-server, single-line, single-phase waiting line system, where $\lambda$ represents the mean arrival rate of customers and $\mu$ represents the mean service rate, what is the formula for the average utilization of the system?

A) $\lambda$ / $\mu$
B) $\lambda$ / ( $\mu$ - $\lambda$ )
C) $\lambda$ ² / $\mu$ ( $\mu$ - $\lambda$ )
D) 1 / ( $\mu$ - $\lambda$ )
E) $\lambda$ / $\mu$ ( $\mu$ - $\lambda$ )

Question 54

For a single-server, single-line, single-phase waiting line system, where $\lambda$ represents the mean arrival rate of customers and $\mu$ represents the mean service rate, what is the formula for the average number of customers waiting in line?

A) $\lambda$ / $\mu$
B) $\lambda$ / ( $\mu$ - $\lambda$ )
C) pL
D) 1 / ( $\mu$ - $\lambda$ )
E) $\lambda$ / $\mu$ ( $\mu$ - $\lambda$ )

Question 55

5⁰ = ________?

A) 5
B) 0
C) undefined
D) 1
E) 1/5

Question 56

Which of the following is not an assumption of the waiting line models presented in the textbook?

A) balking is not allowed
B) reneging is not allowed
C) jockeying is allowed
D) customer arrival rate is described by a Poisson distribution
E) service times are described by an exponential distribution

Question 57

Which of the following is not considered to be a valid performance measure of a waiting line system?

A) the priority used for controlling the line
B) the average number of customers waiting in line
C) the average number of customers in the system
D) the average amount of time customers spend waiting
E) the system utilization rate

Question 58

Which of the following is not an assumption of the waiting line models presented in the textbook?

A) the customers are patient
B) customers come from an infinite population
C) customer arrival rate is described by a Poisson distribution
D) service times are described by an exponential distribution
E) the waiting line priority rule is longest service requirements first

Question 59

For a single-server, single-line, single-phase waiting line system, where $\lambda$ represents the mean arrival rate of customers and $\mu$ represents the mean service rate, what is the formula for the average number of customers in the system?

A) $\lambda$ / $\mu$
B) $\lambda$ / ( $\mu$ - $\lambda$ )
C) $\lambda$ ² / $\mu$ ( $\mu$ - $\lambda$ )
D) 1 / ( $\mu$ - $\lambda$ )
E) $\lambda$ / $\mu$ ( $\mu$ - $\lambda$ )

Question 60

For a single-server, single-line, single-phase waiting line system, where $\lambda$ represents the mean arrival rate of customers and $\mu$ represents the mean service rate, what is the formula for the average time spent waiting in line?

A) $\lambda$ / $\mu$
B) $\lambda$ / ( $\mu$ - $\lambda$ )
C) $\lambda$ ² / $\mu$ ( $\mu$ - $\lambda$ )
D) 1 / ( $\mu$ - $\lambda$ )
E) pW

Question 61

A customer population is called finite when the number of potential new customers is affected by the number of customers already in the system.

Question 62

Reneging occurs when a customer enters a waiting line but decides to exit before being served.

Question 63

For a single-line, multi-server, single-phase waiting line system, where $\lambda$ represents the mean arrival rate of customers and $\mu$ represents the mean service rate for each of s identical servers, what is the formula for the average utilization of the system?

A) $\lambda$ / $\mu$
B) $\lambda$ / ( $\mu$ - $\lambda$ )
C) $\lambda$ / s $\mu$
D) s / ( $\mu$ - $\lambda$ )
E) $\lambda$ / s ( $\mu$ - $\lambda$ )

Question 64

Implementing process improvements or dedication of additional resources is one way to improve:

A) priority rule applications
B) the number of lines required
C) server efficiency
D) service facilities
E) arrival rates

Question 65

Walking occurs when a customer decides not to enter the waiting line.

Question 66

Most larger-scale waiting line systems use ________ simulation.

A) finite queue
B) finite customer
C) nonexponential arrival
D) discrete-event
E) multi-phase

Question 67

Which system performance option to change a waiting line system is related to the concept of division of labor?

A) changing the priority rule
B) changing the number of lines
C) changing the number of phases
D) changing customer arrival rates
E) changing the number of service facilities

Question 68

Assume you have a single channel, single server, and single phase queue. Mean arrival rate is 80/hr and system capacity is 100/hr. What is the average number of customers in the system?

A) 2
B) 8
C) 4
D) 80
E) 0

Question 69

A waiting line occurs whenever there is less customer demand for a service than can be provided.

Question 70

Consider a single-server queuing system (with Poisson arrivals and exponential service times). If the arrival rate is 30 units per hour, and each customer takes 30 seconds on average to be served, what is the average length of the line?

A) 1.03
B) -1.03
C) 0.166
D) 0.333
E) 0.083

Question 71

Customers in a grocery store would be considered a finite customer population.

Question 72

Consider a single-line, single-server waiting line system. The arrival rate ? is 40 people per hour, and the service rate µ is 80 people per hour. What is the average number of customers in line?

A) 0.5
B) 0.025
C) 1.0
D) 0.0125
E) 20.0

Question 73

Consider a single-server queuing system. If the arrival rate is 45 customers per hour and it takes 1 minute on average to serve a customer, what is the average waiting time in the waiting line in minutes?

A) 3
B) 0.05
C) 4
D) 1.02
E) -1.02

Question 74

Vacillating occurs when a customer enters one line and then switches to a different line in an effort to reduce his or her waiting time.

Question 75

From an operations view point, single-phase systems operators must:

A) have greater skills
B) adjust their work schedules
C) be capable of multi-tasking customers
D) be unionized
E) be competitive

Question 76

Visitors to a major amusement park would be considered a finite customer population.

Question 77

Customers walk into a bank at an average rate of 20 per hour. On average, there are 5 people waiting in line to be served. How long does the average customer wait in line?

A) 15 minutes
B) 0.25 minutes
C) 4 minutes
D) 3 minutes
E) 8 minutes

Question 78

The two elements that define a waiting line system are (1) the population source of its customers and (2) the process or service system itself.

Question 79

Consider a single-line, single-server waiting line system. The arrival rate ? is 80 people per hour, and the service rate ? is 120 people per hour. What is the probability of having 3 or more units in the system?

A) 29.63%
B) 33.33%
C) 0.00%
D) 9.88%
E) 66.67%

Question 80

A customer population is called finite when the number of potential new customers is not affected by the number of customers already in the system.