Exam 25: Waiting-Line Models

A manufacturing plant is trying to determine how long the average line for a repair process will be.If 10 machines arrive each hour and must wait 6 minutes in the line,how long will the line be,on average?

In queuing problems,arrival rates are generally described by the normal probability distribution.

Which of the following is a requirement for application of Little's Law to be valid?

Little's Law is not applicable in which of the following situations?

Suppose that 1 customer arrives each minute in a Poisson distribution.Is it more likely that 2 customers or 0 customers will arrive each minute?

What costs are present in waiting line analysis? How do these costs vary with the level of service?

Suppose that a service facility has an average line of 2 customers that must wait,on average,5 minutes for service.How many customers are arriving per hour?

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 before being served.

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

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.

The study of waiting lines calculates the cost of providing good service but does not value the cost of customers' waiting time.

A finite population waiting line model has an average service time T of 200 minutes and an average time between service requirements U of 300 minutes.What is the service factor X?

A(n)________ queuing system has one line and one server.

What are the six assumptions underlying the M/M/1 waiting line model? Which of these also hold for the M/D/1 model?

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.What is the utilization factor?

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

A finite population waiting line model with a single server has an average service time T of 50 minutes and an average time between service requirements U of 350 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.

A waiting line meeting the assumptions of M/M/1 has an average time between arrivals of 20 minutes,and it services items in an average of 10 minutes each.What is the utilization factor?

Which of the following is a measure of queue performance?

A waiting-line system that meets the assumptions of M/M/1 has λ = 1,μ= 4.Calculate Po.Build a table showing the probability of more than 0,1,2,3,4,5,6,and 7 units in the system.Round to six decimal places in your work