Question 1

The manner in which units receive their service,such as FCFS,is the

Accepted Answer

Queue discipline refers to the manner in which units (customers, requests, etc.) receive service from a system. FCFS, or first-come, first-served, is a type of queue discipline. The other options, channel, steady state, and operating characteristic, do not refer specifically to queue discipline.

Question 2

Queue discipline refers to the assumption that a customer has the patience to remain in a slow moving queue.

Accepted Answer

Queue discipline refers to the rules or priorities governing the order in which customers are served in a queue, not their patience level.

Question 3

A waiting line situation where every customer waits in the same line before being served by the same server is called a single server waiting line.

Accepted Answer

False

Question 4

Performance measures dealing with the number of units in line and the time spent waiting are called

Accepted Answer

These types of performance measures are commonly referred to as operating characteristics, which analyze the behavior of a queuing system under varying conditions. These measures can include the average number of units in line or the average time spent waiting, among others.

Question 5

For all waiting lines,P₀ + P_w = 1.

Accepted Answer

The answer of For all waiting lines,P₀ + P_w =...

Question 6

For many waiting line situations,the arrivals occur randomly and independently of other arrivals and it has been found that a good description of the arrival pattern is provided by

Accepted Answer

The given conditions describe a Poisson process, which is a type of arrival pattern where events occur randomly and independently over time. The Poisson distribution is a probability distribution that models this process and is commonly used to analyze waiting line situations. Therefore, the best choice for describing the arrival pattern is a Poisson probability distribution.

Question 7

Operating characteristics formulas for the single-channel queue do NOT require

Accepted Answer

The inequality F1F1F1S1F1F1F10 > F1F1F1S1F1F1F10 is not a requirement for the formulas of operating characteristics in a single-channel queue. It is simply a condition for the stability of the system, ensuring that the arrival rate is not higher than the service rate. Therefore, choices B, C, and D are all requirements for the single-channel queue, but A is not.

Question 8

If arrivals occur according to the Poisson distribution every 20 minutes,then which is NOT true?

Accepted Answer

The answer of If arrivals occur according to the Poisson...

Question 9

In a waiting line situation,arrivals occur,on average,every 10 minutes,and 10 units can be received every hour.What are $\lambda$ and $\mu$?

Accepted Answer

The answer of In a waiting line situation,arrivals occur,on average,every...

Question 10

Which of the following can NOT be found by the queuing formulas presented in the textbook?

Accepted Answer

The queuing formulas presented in the textbook can find the average number of units in the system, the probability that no units are in the system, and the average time a unit spends in the system. However, it cannot find the maximum time a unit spends in the system, as this would require observing the actual time each unit spends in the system and finding the maximum value.

Question 11

The arrival rate in queuing formulas is expressed as

Accepted Answer

The arrival rate in queuing formulas is expressed as the mean number of arrivals per time period. Therefore, choice D is the best choice. The other choices are not correct because the arrival rate is not necessarily the minimum number of arrivals per time period, and it is not the mean time between arrivals or the mean number of arrivals per channel, as these are different measures.

Question 12

For an M/M/1 queuing system,if the service rate,µ,is doubled,the average wait in the system,W,is cut in half.

Accepted Answer

Doubling the service rate (µ) in an M/M/1 queue decreases the average wait time in the system (W) more significantly than just cutting it in half, because W is inversely proportional to the difference between the service rate and the arrival rate (λ), not directly proportional to the service rate alone.

Question 13

What queue discipline is assumed by the waiting line models presented in the textbook?

Accepted Answer

The textbook assumes the first-come first-served queue discipline as the default queue discipline in waiting line models.

Question 14

In a multiple channel system

Accepted Answer

The answer of In a multiple channel system
...

Question 15

The total cost for a waiting line does NOT specifically depend on

Accepted Answer

The total cost for a waiting line depends on the cost of waiting, the cost of service, and the number of units in the system. However, the cost of a lost customer is not directly related to the waiting line, as it is a separate cost that may be incurred if customers become impatient and leave the system before being served. Therefore, D is the correct answer.

Question 16

Models with a finite calling population

Accepted Answer

Models with a finite calling population use the size of the population as a parameter in the operating characteristics formulas. This means that the arrival rate and service rate may be dependent on the number of units in the system, but the key characteristic is the finite nature of the calling population.

Question 17

Decision makers in queuing situations attempt to balance

Accepted Answer

Service levels against service cost is the correct balance that decision makers in queuing situations attempt to achieve. They aim to provide an acceptable level of service while keeping the costs of providing that service as low as possible.

Question 18

The assumption of exponentially distributed service times indicates that

Accepted Answer

In an exponential distribution, the cumulative distribution function (CDF) is given by F(x) = 1 - e^(-λx), where λ is the rate parameter. The mean service time is equal to 1/λ. To find the percentage of service times that are less than the mean, we substitute x = mean = 1/λ into the CDF: F(mean) = 1 - e^(-λ/λ) = 1 - e^(-1) = 0.6321 or approximately 63%. Therefore, the correct answer is C.

Question 19

Use of the Poisson probability distribution assumes that arrivals are not random.

Accepted Answer

The Poisson probability distribution is commonly used to model the number of arrivals in a fixed time period or space, assuming that they occur randomly and independently. Therefore, the use of the Poisson distribution assumes that arrivals are random.

Question 20

Little's flow equations

Accepted Answer

The answer of Little's flow equations
...

Quiz 15: Waiting Line Models

The manner in which units receive their service,such as FCFS,is the

Queue discipline refers to the assumption that a customer has the patience to remain in a slow moving queue.

A waiting line situation where every customer waits in the same line before being served by the same server is called a single server waiting line.

Performance measures dealing with the number of units in line and the time spent waiting are called

For all waiting lines,P₀ + P_w = 1.

For many waiting line situations,the arrivals occur randomly and independently of other arrivals and it has been found that a good description of the arrival pattern is provided by

Operating characteristics formulas for the single-channel queue do NOT require

If arrivals occur according to the Poisson distribution every 20 minutes,then which is NOT true?

In a waiting line situation,arrivals occur,on average,every 10 minutes,and 10 units can be received every hour.What are $\lambda$ and $\mu$ ?

Which of the following can NOT be found by the queuing formulas presented in the textbook?

The arrival rate in queuing formulas is expressed as

For an M/M/1 queuing system,if the service rate,µ,is doubled,the average wait in the system,W,is cut in half.

What queue discipline is assumed by the waiting line models presented in the textbook?

In a multiple channel system

The total cost for a waiting line does NOT specifically depend on

Models with a finite calling population

Decision makers in queuing situations attempt to balance

The assumption of exponentially distributed service times indicates that

Use of the Poisson probability distribution assumes that arrivals are not random.

Little's flow equations

Quiz 15: Waiting Line Models

The manner in which units receive their service,such as FCFS,is the

Queue discipline refers to the assumption that a customer has the patience to remain in a slow moving queue.

A waiting line situation where every customer waits in the same line before being served by the same server is called a single server waiting line.

Performance measures dealing with the number of units in line and the time spent waiting are called

For all waiting lines,P0 + Pw = 1.

For many waiting line situations,the arrivals occur randomly and independently of other arrivals and it has been found that a good description of the arrival pattern is provided by

Operating characteristics formulas for the single-channel queue do NOT require

If arrivals occur according to the Poisson distribution every 20 minutes,then which is NOT true?

In a waiting line situation,arrivals occur,on average,every 10 minutes,and 10 units can be received every hour.What are λ\lambdaλ and μ\muμ ?

Which of the following can NOT be found by the queuing formulas presented in the textbook?

The arrival rate in queuing formulas is expressed as

For an M/M/1 queuing system,if the service rate,µ,is doubled,the average wait in the system,W,is cut in half.

What queue discipline is assumed by the waiting line models presented in the textbook?

In a multiple channel system

The total cost for a waiting line does NOT specifically depend on

Models with a finite calling population

Decision makers in queuing situations attempt to balance

The assumption of exponentially distributed service times indicates that

Use of the Poisson probability distribution assumes that arrivals are not random.

Little's flow equations

For all waiting lines,P₀ + P_w = 1.

In a waiting line situation,arrivals occur,on average,every 10 minutes,and 10 units can be received every hour.What are $\lambda$ and $\mu$ ?