Test-Bank-for-Heizer-Operations-Management-9e

80.A firm has established a distribution network for the supply of a raw material critical to its manufacturing. Currently there are two origins for this raw material, which must be shipped to three manufacturing plants. The current network has the following characteristics:

The firm has identified two potential sites for a third raw material source; these are identified as Candidate A and Candidate B. From A, the costs to ship would be $9 to Plant 1, $10 to Plant 2, and $12 to Plant 3. From B, these costs would be $11, $14, and $8. The new source, wherever it is located, will have a capacity of 500 units. Set up—but DO NOT SOLVE— this problem as though you were going to solve it with transportation problem software.

The setup requires two transportation problems, each with three sources.

(Transportation modeling, moderate) {AACSB: Analytic Skills}

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81.A firm has established a distribution network for the supply of a raw material critical to its manufacturing. Currently there are two origins for this raw material, which must be shipped to three manufacturing plants. The current network has the following characteristics:

The firm has identified two potential sites for a third raw material source; these are identified as Candidate A and Candidate B. From A, the costs to ship would be $9 to Plant 1, $10 to Plant 2, and $12 to Plant 3. From B, these costs would be $11, $14, and $8. The new source, wherever it is located, will have a capacity of 500 units. Solve with the transportation method. Which site should be selected?

This problem requires two transportation problems, each with three sources.

Candidate A should be selected. (The stepping-stone method, difficult) {AACSB: Analytic Skills}

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MODULE D: WAITING-LINE MODELS

TRUE/FALSE

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

True (Introduction, easy)

2.The two characteristics of the waiting line itself are whether its length is limited or unlimited and the discipline of the people or items in it.

True (Characteristics of a waiting-line system, easy)

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

False (Characteristics of a waiting-line system, easy)

4.A copy center has five machines that serve many customers throughout the day; the waiting-line system for copy service has an infinite population while the waiting-line system for copier maintenance has a finite population

True (Characteristics of a waiting-line system, easy)

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

False (Characteristics of a waiting-line system, moderate)

6.Balk and renege are elements of queue discipline.

False (Characteristics of a waiting-line problem, easy)

7.A hospital emergency room always follows a first-in, first-served queue discipline in the interest of fairness.

False (Characteristics of a waiting-line system, moderate)

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

True (Characteristics of a waiting-line system, moderate)

9.A waiting-line system with one waiting line and three sequential processing stages is a multichannel single-phase system.

False (Characteristics of a waiting-line problem, easy)

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

False (Characteristics of a waiting-line system, moderate)

11.The cost of waiting decreases as the service level increases.

True (Queuing costs, moderate)

12.LIFS (last-in, first-served) is a common queue discipline, most often seen where people, not objects, form the waiting line.

False (Characteristics of a waiting-line problem, moderate)

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13.A bank office with five tellers, each with a separate line of customers, exhibits the characteristics of a multi-phase queuing system.

False (Characteristics of a waiting-line system, moderate)

14.In the analysis of queuing models, the Poisson distribution often describes arrival rates and service times are often described by the negative exponential distribution.

True (Characteristics of a waiting-line system, moderate)

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

False (Queuing costs, moderate)

16.As the average service rate μ grows larger, the slope of the distribution of service time probabilities grows larger and larger, eventually becoming positive.

False (The variety of queuing models, easy)

17.Four of the most widely used waiting line models—M/M/1 or A, M/M/S or B, M/D/1 or C, and Limited population or D—all share three characteristics: Poisson arrivals, FIFO discipline, and exponential service times.

False (The variety of queuing models, moderate)

18.In the M/M/1 waiting line model with an arrival rate of 2 per hour and a service rate of 6 per hour, the utilization factor for the system is approximately 0.333.

True (The variety of queuing models, easy) {AACSB: Analytic Skills}

19.The greater the margin by which the arrival rate exceeds the service rate, the better the performance of the waiting line.

False (The variety of queuing models, easy)

20.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.

True (The variety of queuing models, moderate)

21.A finite population waiting line model has an average service time T of 100 minutes and an average time between service requirements U of 400 minutes; the service factor X is 0.25.

False (The variety of queuing models, moderate) {AACSB: Analytic Skills}

MULTIPLE CHOICE

22.Study of waiting-line models helps operations managers better understand

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

e (Introduction, easy)

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23.Which of the following is not a common queuing situation?

a.grocery shoppers being served by checkout clerks

b.commuters slowing or stopping at toll plazas to pay highway tolls

c.machinery waiting to be repaired or maintained

d.parcel delivery truck following its computer-generated route

e.patients in a health clinic waiting to see one of several doctors

d(Introduction, easy)

24.In queuing problems, which of the following probability distributions is typically used to describe the number of arrivals per unit of time?

a.binomial

b.normal

c.Poisson

d.exponential

e.lognormal

c (Characteristics of a waiting-line system, easy)

25.In queuing problems, which of the following probability distributions is typically used to describe the time to perform the service?

a.binomial

b.normal

c.Poisson

d.negative exponential

e.lognormal

d (Characteristics of a waiting-line system, easy)

26.The common measures of a queuing system's performance include

a.probability that the service facility will be idle, average queue length, probability that the waiting time will exceed a specified duration

b.average time each customer spends in the system, probability that the service system will be idle, average time each customer spends in the queue

c.average queue length, maximum time a customer may spend in the queue, the utilization factor for the system

d.average time each customer spends in the system, maximum queue length, probability of a specific number of customers in the system

e.none of the above

b (Characteristics of a waiting-line system, moderate)

27.The shopper who says to himself, “I’ve waited too long in this line. I don’t really need to buy this product today,” and leaves the store is an illustration of which element of arrival behavior?

a.random arrival

b.renege

c.random departure

d.balk

e.none of the above

b (Characteristics of a waiting-line system, moderate)

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28.A waiting line, or queuing, system has three parts, which are

a.distribution of arrival times, discipline while waiting, and distribution of service times

b.arrival rate, service rate, and utilization rate

c.arrival discipline, queue discipline, and service sequencing

d.arrival or inputs, queue discipline or the waiting line itself, and the service facility

e.sequencing policy, penalty for reneging, and expediting of arrivals

d (Characteristics of a waiting-line system, moderate)

29.The source population is considered to be either ________ in its size.

a.finite or infinite

b.fixed or variable

c.known or unknown

d.random or scheduled

e.small or large

a(Characteristics of a waiting-line system, moderate)

30.The potential restaurant customer who says to her husband, “The line looks too long; let's eat somewhere else,” is an illustration of which element of queue discipline?

a.first-in, first-out

b.balk

c.renege

d.random departure

e.none of the above

b (Characteristics of a waiting-line system, moderate)

31.An airline ticket counter, with several agents for one line of customers, is an example of a

a.single channel, single phase system

b.single channel, multi-phase system

c.multi-channel, single phase system

d.multi-channel, multi-phase system

e.none of the above

c (Characteristics of a waiting-line system, moderate)

32.A concert hall, employing both ticket takers and ushers to seat patrons, behaves typically as a

a.multi-channel, single phase system

b.multi-channel, multi-phase system

c.single channel, single phase system

d.single channel, multi-phase system

e.none of the above

b (Characteristics of a waiting-line system, moderate)

33.If the food service for the university operates a cafeteria with a single serving line, that system behaves most like a

a.single channel, single phase system

b.single channel, multi-phase system

c.multi-channel, single phase system

d.multi-channel, multi-phase system

e.none of the above

b (Characteristics of a waiting-line system, moderate)

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34.The sign at the bank that reads “Wait here for the first available teller” suggests the use of a _____

waiting line system.

a.single phase

b.multi-phase

c.single channel

d.multi-channel

e.multiple line

d (Characteristics of a waiting-line system, moderate)

35.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

d (Characteristics of a waiting-line system, moderate)

36.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.multiple-channel, multi-phase, unlimited 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.none of the above

c (Characteristics of a waiting-line system, moderate)

37.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

b (Characteristics of a waiting-line system, moderate)

38.“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.none of the above

a (Characteristics of a waiting-line system, moderate)

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39.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

d (Characteristics of a waiting-line system, moderate)

40.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

a(Characteristics of a waiting-line system, easy)

41.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

a(Characteristics of a waiting-line system, moderate)

42.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

e (Characteristics of a waiting-line system, moderate)

43.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

b (Characteristics of a waiting-line system, easy)

44.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

b (Characteristics of a waiting-line system, moderate)

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45.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

c (The variety of queuing models, moderate) {AACSB: Analytic Skills}

46.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

b (The variety of queuing models, easy) {AACSB: Analytic Skills}

47.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

c (The variety of queuing models, easy)

48.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

e (The variety of queuing models, moderate)

49.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

b (The variety of queuing models, moderate)

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