Exam 15: Waiting Line Models

Adding more servers always improves the operating characteristics of the waiting line and reduces the waiting cost.

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

A company has tool cribs where workmen draw parts.Two men have applied for the position of distributing parts to the workmen.George Fuller is fresh out of trade school and expects a $6 per hour salary.His average service time is 4 minutes.John Cox is a veteran who expects $12 per hour.His average service time is 2 minutes.A workman's time is figured at $10 per hour.Workmen arrive to draw parts at an average rate of 12 per hour. a.What is the average waiting time a workman would spend in the system under each applicant? b.Which applicant should be hired?

In a multiple-channel system

A multiple-channel system has more than one waiting line.

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

Decision makers in queuing situations attempt to balance

Give examples of systems you have seen in which a)blocked arrivals are cleared,and b)there is a finite calling population.

In developing the total cost for a waiting line,waiting cost takes into consideration both the time spent waiting in line and the time spent being served.

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

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

When a waiting system is in steady-state operation,the number of units in the system is not changing.

During summer weekdays,boats arrive at the inlet drawbridge according to the Poisson distribution at a rate of 3 per hour.In a 2-hour period, a.what is the probability that no boats arrive? b.what is the probability that 2 boats arrive? c.what is the probability that 8 boats arrive?

The Quick Snap photo machine at the Lemon County bus station takes four snapshots in exactly 75 seconds.Customers arrive at the machine according to a Poisson distribution at the mean rate of 20 per hour.On the basis of this information,determine the following: a.the average number of customers waiting to use the photo machine b.the average time a customer spends in the system c.the probability an arriving customer must wait for service.

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.

For an M/G/1 system with  = 6 and  = 9,with  = .03,find a.the probability the system is idle. b.the average length of the queue. c.the average number in the system.

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

Single-booth ticket sales at a theater would be an example of which queuing model?

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

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