Question 1

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 2

A dental clinic at which only one dentist works is open only two days a week.During those two days,the traffic arrivals follow a Poisson distribution with patients arriving at the rate of three per hour.The doctor serves patients at the rate of one every 15 minutes.
a.What is the probability that the clinic is empty (except for the dentist and staff)?
b.What is the probability that there are one or more patients in the system?
c.What is the probability that there are four patients in the system?
d.What is the probability that there are four or more patients in the system?

Accepted Answer

(a)Po = 1 - 3/4 = 0.25; (b)The probabili

Question 3

Which of the following occurs as the level of service decreases?

Accepted Answer

A) Cost of waiting time decreases,and cost of providing service decreases. 
B) Cost of waiting time decreases,and cost of providing service increases. 
C) Cost of waiting time increases,and cost of providing service decreases. 
D) Cost of waiting time increases,and cost of providing service increases. 
E) Cost of waiting time first decreases,then increases; while cost of providing service decreases. 
A) Cost of waiting time decreases,and cost of providing service decreases. 
B) Cost of waiting time decreases,and cost of providing service increases. 
C) Cost of waiting time increases,and cost of providing service decreases. 
D) Cost of waiting time increases,and cost of providing service increases. 
E) Cost of waiting time first decreases,then increases; while cost of providing service decreases.

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

In the basic queuing model (M/M/1),what probability distribution describes arrival rates?

Accepted Answer

A) continuous 
B) normal 
C) negative exponential 
D) Poisson 
E) lognormal 
A) continuous 
B) normal 
C) negative exponential 
D) Poisson 
E) lognormal

Question 6

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 7

What are Ls and Lq,as used in waiting line terminology? Which is larger,Ls or Lq? Explain.

Accepted Answer

Ls is the average number of units in the

Question 8

A waiting-line system that meets the assumptions of M/M/S has λ = 5,μ = 4,and M = 2.For these values,Po is approximately 0.23077,and Ls is approximately 2.05128.What is the average number of units waiting in the queue?

Accepted Answer

A) approximately 0.1603 
B) approximately 0.4103 
C) approximately 0.8013 
D) approximately 1.0417 
E) Cannot be calculated because λ is larger than μ. 
A) approximately 0.1603 
B) approximately 0.4103 
C) approximately 0.8013 
D) approximately 1.0417 
E) Cannot be calculated because λ is larger than μ.

Question 9

In the basic queuing model (M/M/1),what probability distribution describes service times?

Accepted Answer

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

Question 10

Which of the following is NOT a measure of a queue's performance?

Accepted Answer

A) average time spent in the queue 
B) average queue length 
C) probability that the service facility will be idle 
D) utilization factor for the system 
E) All of the above are performance measures. 
A) average time spent in the queue 
B) average queue length 
C) probability that the service facility will be idle 
D) utilization factor for the system 
E) All of the above are performance measures.

Question 11

The ________ probability distribution is a continuous probability distribution often used to describe the service time in a queuing system.

Accepted Answer

negative e

Question 12

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 which...

Question 13

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

Accepted Answer

A) 0.0625 
B) 0.25 
C) 0.75 
D) 0.9375 
E) 1.00 
A) 0.0625 
B) 0.25 
C) 0.75 
D) 0.9375 
E) 1.00

Question 14

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

Accepted Answer

If the service rate is not gre

Question 15

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 probability that the waiting line is empty?

Accepted Answer

Po = 1 - λ

Question 16

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,queu

Question 17

A crew of mechanics at the Highway Department Garage repair vehicles that break down at an average of λ = 7 vehicles per day (approximately Poisson in nature).The mechanic crew can service an average of μ= 11 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 waiting for service at any one time?

Accepted Answer

(a)Utilization is 7 / 11 = .63

Question 18

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.A student has just entered the system.How long is she expected to stay in the system?

Accepted Answer

A) 0.125 minutes 
B) 0.9 minutes 
C) 1.5 minutes 
D) 7.5 minutes 
E) 0.075 hours 
A) 0.125 minutes 
B) 0.9 minutes 
C) 1.5 minutes 
D) 7.5 minutes 
E) 0.075 hours

Question 19

Which one of the following is NOT a characteristic of a Model A or M/M/1 system?

Accepted Answer

A) exponential service time pattern 
B) single number of servers 
C) single number of phases 
D) Poisson arrival rate pattern 
E) limited population size 
A) exponential service time pattern 
B) single number of servers 
C) single number of phases 
D) Poisson arrival rate pattern 
E) limited population size

Question 20

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 which of the following?

Accepted Answer

A) multiple-server,limited queue length 
B) single-server,multiphase,limited queue length 
C) multiple-server,unlimited queue length 
D) multiple single-server systems,limited queue length 
E) single-server,unlimited queue length 
A) multiple-server,limited queue length 
B) single-server,multiphase,limited queue length 
C) multiple-server,unlimited queue length 
D) multiple single-server systems,limited queue length 
E) single-server,unlimited queue length

Exam 25: Waiting-Line Models

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

Which of the following occurs as the level of service decreases?

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.

In the basic queuing model (M/M/1),what probability distribution describes arrival rates?

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

What are Ls and Lq,as used in waiting line terminology? Which is larger,Ls or Lq? Explain.

A waiting-line system that meets the assumptions of M/M/S has λ = 5,μ = 4,and M = 2.For these values,Po is approximately 0.23077,and Ls is approximately 2.05128.What is the average number of units waiting in the queue?

In the basic queuing model (M/M/1),what probability distribution describes service times?

Which of the following is NOT a measure of a queue's performance?

The ________ probability distribution is a continuous probability distribution often used to describe the service time in a queuing system.

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

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

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

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 probability that the waiting line is empty?

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

Which one of the following is NOT a characteristic of a Model A or M/M/1 system?

Operations and Productivity

Operations Strategy in a Global Environment

Project Management

Forecasting

Design of Goods and Services

Managing Quality

Process Strategy

Capacity and Constraint Management

Location Strategies

Layout Strategies

Human Resources, job Design, and Work Measurement

Supply Chain Management

Inventory Management

Aggregate Planning and Sop

Material Requirements Planning Mrpand Erp

Short-Term Scheduling

Jit, tps, and Lean Operations

Maintenance and Reliability

Sustainability in the Supply Chain

Statistical Process Control

Supply Chain Management Analytics

Decision-Making Tools

Linear Programming

Transportation Models

Learning Curves

Simulation

Filters

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