Exam 12: Queueing Models

A queuing system where customers join a single line and then are served by the first available server are said to be:

When a customer already in line in a queuing system becomes impatient and leaves the system before starting service,this is called:

Server utilization is the:

​The server utilization U in an M/M/s system is always the same as the traffic intensity.

The decision to balk at entering a queuing system can be made by the customer or the system.

The two basic modeling approaches for queuing systems are optimization and simulation.

Which of the following is not one of the types of service disciplines

Exhibit 12-1 A grocery store manager would like to use an analytical queueing model to study the lines of customers that form in front of the checkout stations in the store. During a period of time when business is steady, several store employees have gathered data on customer interarrival times, which are shown below. -[Part 3] Refer to Exhibit 12-1.Again assuming an exponential distribution with the parameter λ you obtained in Part 2,what is the probability that a customer interarrival time will be more than 2 minutes,but less than 5 minutes

In an Erlang loss model,customers who arrive when all servers are busy are lost to the system.

Exhibit 12-2 An oil-change facility serves customers that enter at a rate of 8 per hour. There are five servers available to perform oil changes for entering customers. Customers wait in a single line and enter the facility, in first-come-first-serve fashion, to the first of the five servers who is available. Each server can change the oil of one customer's car every 30 minutes on average. -Refer to Exhibit 12-2.What is the server utilization