Question 1

A waiting line or ________ is where items or people are in a line awaiting service; ________ is a body of knowledge about waiting lines.

Accepted Answer

queue; que

Question 2

A manufacturing plant is trying to determine how long the average line for a repair process will be. If 12 machines arrive each hour and must wait 8 minutes in the line, how long will the line be, on average?

Accepted Answer

Little's Law X machines = 12 m

Question 3

A(n) ________ queuing system has one line and one server.

Accepted Answer

The answer of A(n) ________ queuing system has one line...

Question 4

What is the waiting-line problem? Why is it important to operations?

Accepted Answer

A waiting-line problem concerns the ques

Question 5

Why must the service rate be greater than the arrival rate in a single-channel system?

Accepted Answer

If the service rate is not gre

Question 6

A crew of mechanics at the Highway Department garage repair vehicles that break down at an average of λ = 7.5 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 utilization rate for this service system?
b. What is the average time before the facility can return a breakdown to service?
c. How much of that time is spent waiting for service?
d. How many vehicles are likely to be in the system at any one time?

Accepted Answer

(a) Utilization is ρ = 7.5 / 1

Question 7

Why does it matter whether a population of arrivals is limited or unlimited? Compose your answer in a well-organized, convincing paragraph.

Accepted Answer

If an arrival population is unlimited, t

Question 8

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

Accepted Answer

A)  binomial 
B)  normal 
C)  Poisson 
D)  exponential 
E)  lognormal 
A)  binomial 
B)  normal 
C)  Poisson 
D)  exponential 
E)  lognormal

Question 9

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

Accepted Answer

A)  single channel, single phase system. 
B)  single channel, multiphase system. 
C)  multichannel, single phase system. 
D)  multichannel, multiphase system. 
E)  multichannel, cross-phase system. 
A)  single channel, single phase system. 
B)  single channel, multiphase system. 
C)  multichannel, single phase system. 
D)  multichannel, multiphase system. 
E)  multichannel, cross-phase system.

Question 10

A crew of mechanics at the Highway Department garage repair vehicles that break down at an average of λ = 8 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 - 8/10 = 0.20; (b)

Question 11

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 12

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

Accepted Answer

A)  priority 
B)  random 
C)  FIFO or FIFS 
D)  LIFO or LIFS 
E)  SPT 
A)  priority 
B)  random 
C)  FIFO or FIFS 
D)  LIFO or LIFS 
E)  SPT

Question 13

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

Accepted Answer

A)  single channel, single phase system. 
B)  single channel, multiphase system. 
C)  multichannel, single phase system. 
D)  multichannel, multiphase system. 
E)  multichannel, cross-phase system. 
A)  single channel, single phase system. 
B)  single channel, multiphase system. 
C)  multichannel, single phase system. 
D)  multichannel, multiphase system. 
E)  multichannel, cross-phase system.

Question 14

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

Accepted Answer

A) True 
 B)False

Question 15

You have seen that, in an M/D/1 problem, the average queue length is exactly one-half the average queue length of an otherwise identical M/M/1 problem. Are all other performance statistics one-half as large also? Explain.

Accepted Answer

Only the average queue length

Question 16

A(n) ________ queuing system is one in which the customer receives service from only one station and then exits the system.

Accepted Answer

The answer of A(n) ________ queuing system is one in...

Question 17

Students arrive randomly at the help desk of the computer lab. There is only one service agent, and the time required for inquiry varies from student to student. Arrival rates have been found to follow the Poisson distribution, and the service times follow the negative exponential distribution. The average arrival rate is 12 students per hour, and the average service rate is 20 students per hour. What is the average service time for this problem?

Accepted Answer

A)  1 minute 
B)  2 minutes 
C)  3 minutes 
D)  5 minutes 
E)  20 minutes 
A)  1 minute 
B)  2 minutes 
C)  3 minutes 
D)  5 minutes 
E)  20 minutes

Question 18

Customers take a number as they join the waiting line of the customer service counter at a discount store. There are two customer service agents. Provide the most likely characteristics of this system.
a. name of model
b. number of channels
c. number of phases
d. arrival rate distribution
e. service time distribution
f. population size
g. queue discipline

Accepted Answer

Multichannel system

Question 19

Students arrive randomly at the help desk of a computer lab. There is only one service agent, and the service time varies from one student to the other. Provide the most likely characteristics for this system.
a. name of model
b. number of channels
c. number of phases
d. arrival rate distribution
e. service time distribution
f. population size
g. queue discipline

Accepted Answer

Single channel syste

Question 20

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

Exam 21: Waiting-Line Models

A waiting line or ________ is where items or people are in a line awaiting service; ________ is a body of knowledge about waiting lines.

A manufacturing plant is trying to determine how long the average line for a repair process will be. If 12 machines arrive each hour and must wait 8 minutes in the line, how long will the line be, on average?

A(n) ________ queuing system has one line and one server.

What is the waiting-line problem? Why is it important to operations?

Why must the service rate be greater than the arrival rate in a single-channel system?

Why does it matter whether a population of arrivals is limited or unlimited? Compose your answer in a well-organized, convincing paragraph.

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

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

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

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

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

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

You have seen that, in an M/D/1 problem, the average queue length is exactly one-half the average queue length of an otherwise identical M/M/1 problem. Are all other performance statistics one-half as large also? Explain.

A(n) ________ queuing system is one in which the customer receives service from only one station and then exits the system.

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

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A waiting line or is where items or people are in a line awaiting service; is a body of knowledge about waiting lines.