Exam 15: Waiting Line Models

arrow
  • Select Tags
search iconSearch Question
flashcardsStudy Flashcards
  • Select Tags

The assumption of exponentially distributed service times indicates that

(Multiple Choice)
4.8/5
(41)

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

(Multiple Choice)
4.8/5
(35)

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

(Multiple Choice)
4.7/5
(39)

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.

(True/False)
4.8/5
(36)

Queue discipline refers to the manner in which waiting units are arranged for service.

(True/False)
4.8/5
(34)

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.

(True/False)
4.7/5
(33)

In waiting line systems where the length of the waiting line is limited,the mean number of units entering the system might be less than the arrival rate.

(True/False)
4.8/5
(37)

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

(Multiple Choice)
4.8/5
(39)

The Grand Movie Theater has one box office clerk.On average,each customer that comes to see a movie can be sold its ticket at the rate of 6 per minute.For the theater's normal offerings of older movies,customers arrive at the rate of 3 per minute.Assume arrivals follow the Poisson distribution and service times follow the exponential distribution. a.What is the average number of customers waiting in line? b.What is the average time a customer spends in the waiting line? c.What is the average number of customers in the system? d.What is a customer's average time in the system? e.What is the probability that someone will be buying tickets when an arrival occurs? The Grand has booked the Stars Wars Trilogy and expects more customers.From conversations with other theater owners,it estimates that the arrival rate will increase to 10 per minute.Output is supplied for a two-cashier and a three-cashier system. Number of Channels 2 3 Arrival Rate 10 10 Service Rate 6 6 Probability of No Units in System 0909 1727 Average Waiting Time 3788 0375 Average Time in System 5455 2041 Average Number Waiting 3.7879 3747 Average Number in System 5.4545 2.0414 Probability of Waiting 7576 2998 Frobability of 11 in System .0245 1ess than .0088 f The Grand has space for ten customers to wait indoors to buy tickets. Which system will be better? g. Do you think it is more sensible for them to continue the one-cashier system?

(Essay)
4.8/5
(30)

In waiting line applications,the exponential probability distribution indicates that approximately 63 percent of the service times are less than the mean service time.

(True/False)
4.9/5
(30)

​Diagram the servers and arrivals in the single and multiple channel models.Designate the line and the system.

(Essay)
4.9/5
(37)

Arrivals at a box office in the hour before the show follow the Poisson distribution with λ = 7 per minute.Service times are constant at 7.5 seconds.Find the average length of the waiting line.

(Essay)
4.8/5
(39)

Quick Clean Rooter cleans out clogged drains.Due to the competitive nature of the drain cleaning business,if a customer calls Quick Clean and finds the line busy,they immediately try another company and Quick Clean loses the business. Quick Clean management estimates that on the average,a customer tries to call Quick Clean every three minutes and the average time to take a service order is 200 seconds.The company wishes to hire enough operators so that at most 4% of its potential customers get the busy signal. a.How many operators should be hired to meet this objective? b.Given your answer to a),what is the probability that all the operators are idle?

(Essay)
4.8/5
(31)

​The machine repair problem is an application of the M/M/1 model with

(Multiple Choice)
4.7/5
(30)

Little's flow equations apply to any waiting line model.

(True/False)
4.9/5
(36)

The Arctic Flyers minor league hockey team has one box office clerk.On average,each customer that comes to see a game can be sold a ticket at the rate of 8 per minute.For normal games,customers arrive at the rate of 5 per minute.Assume arrivals follow the Poisson distribution and service times follow the exponential distribution. a.What is the average number of customers waiting in line? b.What is the average time a customer spends in the waiting line? c.What is the average number of customers in the system? d.What is a customer's average time in the system? e.What is the probability that someone will be buying tickets when an arrival occurs? The Flyers are playing in the league playoffs and anticipate more fans,estimating that the arrival rate will increase to 12 per minute.Output is supplied for a two-cashier and a three-cashier system. Number of Channels 2 3 Arrival Rate 12 12 Service Rate 8 8 Probability of No Units in System 1429 2105 Average Waiting Time 1607 0197 Average Time in System 2857 1447 Average Number Waiting 1.9286 2368 Average Number in System 3.4286 1.7368 Probability of Waiting 6429 2368 Probability of 7 in System .0381 .0074 The rink has space for six customers to wait indoors to buy tickets. Which system will be better? g. Do you think it is more sensible for them to continue the one cashier system?

(Essay)
4.7/5
(35)

The post office uses a multiple channel queue,where customers wait in a single line for the first available window.If the average service time is 1 minute and the arrival rate is 7 customers every five minutes,find,when two service windows are open, a.the probability both windows are idle. b.the probability a customer will have to wait. c.the average time a customer is in line. d.the average time a customer is in the post office.

(Essay)
4.9/5
(32)

In a multiple channel system

(Multiple Choice)
4.9/5
(32)

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

(True/False)
4.7/5
(31)

The assumption that arrivals follow a Poisson probability distribution is equivalent to the assumption that the time between arrivals has​

(Multiple Choice)
4.9/5
(31)
Showing 21 - 40 of 66
close modal

Filters

  • Essay(0)
  • Multiple Choice(0)
  • Short Answer(0)
  • True False(0)
  • Matching(0)