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Of the three types of queue discipline, only ________ is assumed by the four primary waiting line models.

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FIFO or FI...

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A waiting-line system has three parts: the size of the arrival population, the behaviour of arrivals, and the statistical distribution of arrivals.

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

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Queue discipline is the rule that determ...

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A small hair styling salon has several operators. While customers do not have appointments, each is waiting to be served by a specific operator. This scenario provides an example of a


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

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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. The average number of units waiting in the queue


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

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In the analysis of queuing models, the Poisson distribution often describes arrival rates and service times are often described by the negative exponential distribution.

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What are the components in a waiting-line system?

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The components of a waiting-li...

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An M/M/1 model and an M/D/1 model each have an arrival rate of 1 per minute and a service rate of 3 per minute; the average queue length of the M/M/1 will be twice that of the M/D/1.

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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. The average time a unit spends in this system


A) is approximately 0.1603.
B) is approximately 0.2083.
C) is approximately 0.4103.
D) is approximately 0.8013.
E) cannot be calculated because λ is larger than μ.

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On a typical Friday, an average of 12 customers per hour arrive at the bank to transact business. There is one teller at the bank, and the average time required to transact business is four minutes. It is assumed that service times may be described by the exponential distribution. A single line would be used, and the customer at the front of the line would go to the first available bank teller. If a single teller is used, find: a) The average time in the line. b) The average number in the line. c) The average time in the system. d) The average number in the system. e) The probability that the bank is empty. f) If the business is considering adding a second teller (who would work at the same rate as the first) to reduce the waiting time for customers. She assumes that this will cut the waiting time in half. If a second teller is added, find the new answers to parts (a) to (e).

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Which of the following is a measure of queue performance?


A) utilization factor
B) average queue length
C) probability of a specific number of customers in the system
D) average waiting time in the line
E) all of the above

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What does it mean to have a patient customer in a waiting line?

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A patient customer is one who ...

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Four of the most widely used waiting line models-M/M/1 or A, M/M/S or B, M/D/1 or C, and Limited population or D-all share three characteristics, which are


A) normal arrivals, FIFO discipline, and normal service times.
B) Poisson arrivals, FIFO discipline, and a single-service phase.
C) Poisson arrivals, FIFO discipline, and exponential service times.
D) Poisson arrivals, no queue discipline, and exponential service times.
E) Poisson arrivals, long queue discipline, and multiple service times.

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A dental clinic at which only one dentist works is open only two days a week. During those two days, the traffic is uniformly busy 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)? b. What percentage of the time is the dentist busy? c. What is the average number of patients in the waiting room? d. What is the average time a patient spends in the office (wait plus service)? e. What is the average time a patient waits for service?

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

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


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) customers arriving at a coffee shop

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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 in the text.

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

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A queuing model which follows the M/M/1 assumptions has λ = 10 and μ = 12. The average number in the system is


A) 0.83.
B) 2.
C) 2.5.
D) 5.
E) 6.

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The greater the margin by which the arrival rate exceeds the service rate, the better the performance of the waiting line.

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A(n) ________ occurs when an arrival refuses to enter a waiting line; a(n) ________ occurs when an arrival joins a waiting line, then leaves it.

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

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