Question 1

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

Accepted Answer

A) True 
 B)False

Question 2

What is queue discipline?
 State three rules for queue discipline. Which of these rules appears most frequently in the four main models?

Accepted Answer

Queue discipline is the rule that determ

Question 3

A finite population waiting line model with a single server has an average service time T of 200 minutes and an average time between service requirements U of 300 minutes. Calculate the service factor X. If the population consists of 5 elements, what are the average number waiting, the average number being serviced, and the average number running?
 Refer to Table D.8.

Accepted Answer

The service factor is X = T / (T + U) =

Question 4

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 5

A waiting line meeting the M/M/1 assumptions has an arrival rate of 4 per hour and a service rate of 12 per hour. What is the average time a unit spends in the system and the average time a unit spends waiting?

Accepted Answer

Ws = 1 / ( μ- λ) = 1

Question 6

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

Accepted Answer

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 
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

Question 7

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

Accepted Answer

A waiting-line problem concerns the ques

Question 8

A waiting-line system that meets the assumptions of M/M/1 has λ = 1, μ = 4. For this system, the probability of more than two units in the system is approximately

Accepted Answer

A)  zero 
B)  0.015625 
C)  0.0625 
D)  0.25 
E)  0.9375 
A)  zero 
B)  0.015625 
C)  0.0625 
D)  0.25 
E)  0.9375

Question 9

The cost of waiting decreases as the service level increases.

Accepted Answer

A) True 
 B)False

Question 10

Which of the following is not an assumption of the M/M/1 model?

Accepted Answer

A)  The first customers to arrive are the first customers served. 
B)  Each arrival comes independently of the arrival immediately before and after that arrival. 
C)  The population from which the arrivals come is very large or infinite in size. 
D)  Customers do not renege. 
E)  Service times occur according to a normal curve. 
A)  The first customers to arrive are the first customers served. 
B)  Each arrival comes independently of the arrival immediately before and after that arrival. 
C)  The population from which the arrivals come is very large or infinite in size. 
D)  Customers do not renege. 
E)  Service times occur according to a normal curve.

Question 11

The common measures of a queuing system's performance include

Accepted Answer

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 
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

Question 12

Which of the following is an example of a finite arrival population?

Accepted Answer

A)  copy machines in a copying shop that break down 
B)  students at a large university registering for classes 
C)  shoppers arriving at a supermarket 
D)  cars arriving at a suburban car wash 
E)  all of the above 
A)  copy machines in a copying shop that break down 
B)  students at a large university registering for classes 
C)  shoppers arriving at a supermarket 
D)  cars arriving at a suburban car wash 
E)  all of the above

Question 13

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 14

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

Accepted Answer

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)  a single-phase system 
B)  a single channel system 
C)  a multiple-channel system 
D)  a multiple-phase system 
E)  none of the above

Question 15

A waiting line meeting the M/M/1 assumptions has an arrival rate of 10 per hour and a service rate of 12 per hour. What is the average time a unit spends in the system and the average time a unit spends waiting?

Accepted Answer

Ws = 1 / (μ - λ) = 1

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

What is queue discipline? State three rules for queue discipline. Which of these rules appears most frequently in the four main models?

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.

A waiting line meeting the M/M/1 assumptions has an arrival rate of 4 per hour and a service rate of 12 per hour. What is the average time a unit spends in the system and the average time a unit spends waiting?

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

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

A waiting-line system that meets the assumptions of M/M/1 has λ = 1, μ = 4. For this system, the probability of more than two units in the system is approximately

The cost of waiting decreases as the service level increases.

Which of the following is not an assumption of the M/M/1 model?

The common measures of a queuing system's performance include

Which of the following is an example of a finite arrival population?

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

A waiting line meeting the M/M/1 assumptions has an arrival rate of 10 per hour and a service rate of 12 per hour. What is the average time a unit spends in the system and the average time a unit spends waiting?

Operations and Productivity

Operations Strategy in a Global Environment

Project Management

Forecasting

Design of Goods and Services

Managing Quality

Statistical Process Control

Process Strategy

Capacity and Constraint Management

Location Strategies

Layout Strategies

Human Resources, Job Design, and Work Measurement

Supply-Chain Management

Outsourcing as a Supply-Chain Strategy

Inventory Management

Aggregate Planning

Material Requirements Planning MRP and ERP

Short-Term Scheduling

Just-In-Time and Lean Options

Maintenance and Reliability

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Exam 24: Waiting-Line Models

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

What is queue discipline? State three rules for queue discipline. Which of these rules appears most frequently in the four main models?

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.

A waiting line meeting the M/M/1 assumptions has an arrival rate of 4 per hour and a service rate of 12 per hour. What is the average time a unit spends in the system and the average time a unit spends waiting?

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

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

A waiting-line system that meets the assumptions of M/M/1 has λ = 1, μ = 4. For this system, the probability of more than two units in the system is approximately

The cost of waiting decreases as the service level increases.

Which of the following is not an assumption of the M/M/1 model?

The common measures of a queuing system's performance include

Which of the following is an example of a finite arrival population?

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

A waiting line meeting the M/M/1 assumptions has an arrival rate of 10 per hour and a service rate of 12 per hour. What is the average time a unit spends in the system and the average time a unit spends waiting?

Operations and Productivity

Operations Strategy in a Global Environment

Project Management

Forecasting

Design of Goods and Services

Managing Quality

Statistical Process Control

Process Strategy

Capacity and Constraint Management

Location Strategies

Layout Strategies

Human Resources, Job Design, and Work Measurement

Supply-Chain Management

Outsourcing as a Supply-Chain Strategy

Inventory Management

Aggregate Planning

Material Requirements Planning MRP and ERP

Short-Term Scheduling

Just-In-Time and Lean Options

Maintenance and Reliability

Decision-Making Tools

Linear Programming

Transportation Models

Learning Curves

Simulation

Filters