Closed Queueing Network :

A closed queueing network does not have any external arrivals or departures. It represents a situation where a fixed number of jobs circulate in the system, moving from one queue to the next, getting served at individual queues. No jobs enter the system nor does any job leave the system.

Studying the Performance of a Queue :

A Queue or a Queueing Network may be studied in two ways

In this course, we mainly consider analytical approaches to study the performance of queueing systems. Some discussion on simulation techniques for queueing systems will be considered in a later module.

For both analysis and simulations, we need to formulate the model of the queue or the queueing network and give the appropriate input specifications. The analytical approach then computes performance results for the system based on the queueing model and appropriate analytical techniques. The simulation approach essentially runs a simulation model of the given system with the specified inputs in order to obtain the desired performance results that are required to be computed.