Exam 18: A: Waiting-Line Analysis

The following questions refer to this data for a multiple server, priority service queuing model: -What is the average number of low priority items waiting in line for service?

The following questions refer to this data for a multiple server, priority service queuing model: -What is average time in the system for a low priority item?

Infinite source queuing models basically apply only to underloaded systems in which waiting lines can form.

For a server that already has a high utilization ratio,decreasing service capacity will only have a negligible effect on customer waiting time.

Which one of the following measures of system performance is a key measure?

How many spaces should be provided to have a 96% probability of accommodating all of the waiting cars?

All of the following are characteristics of the waiting line system that affect the choice of the queuing model EXCEPT:

A single bay car wash with a Poisson arrival rate and an exponential service time has cars arriving an average of 10 minutes apart,and an average service time of four minutes.The server utilization is:

Which of the following is not an assumption of an infinite source,multiple servers with priority queuing model?

The following questions refer to this data for a multiple server, priority service queuing model: -What is the average number of all items waiting in line for service?

In waiting-line analysis,queue discipline refers to the willingness of customers to wait in line for service.

Customers filter into a record shop at an average of 1 per minute (Poisson)where the service rate is 15 per hour (Poisson). Determine the following: (i)the average number of customers in the system with 8 servers (ii)the minimum number of servers needed to keep the average time in the system to less than 6 minutes

In an infinite source model,the average number being served is equal to the ratio of the average arrival rate to the average service rate.

The multiple server queuing table cannot be applied to single server systems.

All infinite source queuing models require the server utilization to be less than 1.0.

Two trouble-shooters handle service calls for 10 machines.The average time between service requirements is 18 days,and service time averages 2 days.Assume exponential distributions.While running,each machine can produce 1,500 pieces per day.Determine: (i)the percentage of time trouble-shooters are idle (ii)each machine's net productivity (iii)If trouble-shooters represent a cost of $150 per day,and machine downtime cost is $600 per day,would another trouble-shooter be justified? Explain.