Question 1

Which of the following represents a customer that reneged due to the waiting-line?

Accepted Answer

A)  A husband and wife decide to eat out instead after seeing the movie ticket line. 
B)  A car drives past the first fast-food restaurant on Hamburger Row because the drive-through was full. 
C)  A Black Friday shopper skipped one store because the line went around the building. 
D)  A student ordered pizza online because the phone line was busy. 
E)  A customer at a gas station went inside to buy a soda, but after waiting in line for a minute left the soda behind and went outside empty-handed. 
A)  A husband and wife decide to eat out instead after seeing the movie ticket line. 
B)  A car drives past the first fast-food restaurant on Hamburger Row because the drive-through was full. 
C)  A Black Friday shopper skipped one store because the line went around the building. 
D)  A student ordered pizza online because the phone line was busy. 
E)  A customer at a gas station went inside to buy a soda, but after waiting in line for a minute left the soda behind and went outside empty-handed.

Question 2

Suppose that a service facility has an average line of 2 customers that must wait, on average, 5 minutes for service. How many customers are arriving per hour?

Accepted Answer

Use Little's Law that 2 custom

Question 3

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

Accepted Answer

A) True 
 B)False

Question 4

Which of the following is most likely to violate a FIFO queue?

Accepted Answer

A)  supermarket with no express lanes 
B)  car repair garage 
C)  emergency room 
D)  fast-food restaurant 
E)  All of the above are equally likely to violate a FIFO queue. 
A)  supermarket with no express lanes 
B)  car repair garage 
C)  emergency room 
D)  fast-food restaurant 
E)  All of the above are equally likely to violate a FIFO queue.

Question 5

Genco, Inc., a small manufacturer of diesel-generator sets has four shearing machines. Because of the age of these machines, they need minor repairs after 30 hours of use. Analysis of previous breakdowns indicates that breakdowns follow a Poisson distribution. The facility employs one repairman specifically to repair these machines. Average repair time is two hours following an exponential distribution.
a. What is the service factor for this system?
b. What is the average number of these machines in service?
c. What is the impact of adding a second repairman?

Accepted Answer

(a) X = 2/(2+30) = .0625; (b) 4 - .2987

Question 6

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 7

In an earlier chapter, you were introduced to a "traditional" view of costs and a "full cost" view of costs, with respect to a certain type of analysis. How might that lesson apply here? In particular, might operations managers pay more attention to some kinds of costs than others?

Accepted Answer

This is a critical-thinking exercise for

Question 8

Which of the following is not a common queuing situation?

Accepted Answer

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 
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

Question 9

A(n) __________ is a discrete probability distribution that often describes the arrival rate in queuing theory.

Accepted Answer

Poisson di

Question 10

A queuing model which follows the M/M/1 assumptions has λ = 2 and μ = 3. The average number in the system is

Accepted Answer

A)  2/3 
B)  1 
C)  1.5 
D)  2 
E)  6 
A)  2/3 
B)  1 
C)  1.5 
D)  2 
E)  6

Question 11

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

Accepted Answer

A) True 
 B)False

Question 12

A waiting-line system that meets the assumptions of M/M/1 has = 1, = 4. Calculate Po. Build a table showing the probability of more than 0, 1, 2, 3, 4, 5, 6,and 7 units in the system. Round to six decimal places in your work

Accepted Answer

Question 13

A crew of mechanics at the Highway Department garage repair vehicles which 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) P

Question 14

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.

Accepted Answer

A) True 
 B)False

Question 15

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 16

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

Accepted Answer

A) True 
 B)False

Question 17

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?

Accepted Answer

A)  first-in, first-out 
B)  balk 
C)  renege 
D)  random departure 
E)  none of the above 
A)  first-in, first-out 
B)  balk 
C)  renege 
D)  random departure 
E)  none of the above

Question 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.

Accepted Answer

A) True 
 B)False

Question 19

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

Accepted Answer

A)  dynamic-channel 
B)  random-channel 
C)  single channel 
D)  multi-channel 
E)  multiple line 
A)  dynamic-channel 
B)  random-channel 
C)  single channel 
D)  multi-channel 
E)  multiple line

Question 20

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

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

Which of the following represents a customer that reneged due to the waiting-line?

Suppose that a service facility has an average line of 2 customers that must wait, on average, 5 minutes for service. How many customers are arriving per hour?

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

Which of the following is most likely to violate a FIFO queue?

In an earlier chapter, you were introduced to a "traditional" view of costs and a "full cost" view of costs, with respect to a certain type of analysis. How might that lesson apply here? In particular, might operations managers pay more attention to some kinds of costs than others?

Which of the following is not a common queuing situation?

A(n) __________ is a discrete probability distribution that often describes the arrival rate in queuing theory.

A queuing model which follows the M/M/1 assumptions has λ = 2 and μ = 3. The average number in the system is

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

A waiting-line system that meets the assumptions of M/M/1 has = 1, = 4. Calculate Po. Build a table showing the probability of more than 0, 1, 2, 3, 4, 5, 6,and 7 units in the system. Round to six decimal places in your work

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.

Study of waiting-line models helps operations managers better understand

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

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?

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.

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

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

Operations and Productivity

Operations Strategy in a Global Environment

Project Management

Forecasting

Design of Goods and Services

Managing Quality

Process Strategy

Location Strategies

Layout Strategies

Human Resources, Job Design, and Work Measurement

Supply-Chain Management

Inventory Management

Aggregate Planning

Material Requirements Planning Mrp and Erp

Short-Term Scheduling

Just-In-Time and Lean Options

Maintenance and Reliability

Statistical Tools for Managers

Acceptance Sampling

The Simplex Method of Linear Programming

Vehicle Routing and Scheduling

Managing Quality

Process Strategy

Supply-Chain Management

Vehicle Routing and Scheduling

Filters

A waiting-line system that meets the assumptions of M/M/1 has = 1, = 4. Calculate P_o. Build a table showing the probability of more than 0, 1, 2, 3, 4, 5, 6,and 7 units in the system. Round to six decimal places in your work