Exam 24: Waiting-Line Models

In an earlier chapter,you were introduced to a "traditional" view of costs and a "full cost" view of costs,with respect to a certain type of analysis.How might that lesson apply here? In particular,might operations managers pay more attention to some kinds of costs than others?

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?

A crew of mechanics at the Highway Department garage repair vehicles that break down at an average of λ = 8 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 probability that the system is empty? b.What is the probability that there is precisely one vehicle in the system? c.What is the probability that there is more than one vehicle in the system? d.What is the probability of 5 or more vehicles in the system?

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

Balk and renege are elements of queue discipline.

A waiting-line system with one waiting line and three sequential processing stages is a multi-channel single-phase system.

What are the components in a waiting-line system?

The shopper who says to himself,"I've waited too long in this line.I don't really need to buy this product today," and leaves the store is an illustration of which element of arrival behavior?

Describe the difference between FIFO and LIFO queue disciplines.

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

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

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

Arrivals or inputs to a waiting-line system have characteristics that include

A single-phase waiting-line system meets the assumptions of constant service time or M/D/1.Units arrive at this system every 10 minutes on average.Service takes a constant 4 minutes.The average length of the queue is

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.