# Queuing Analysis (A Practical Guide for Computer Scientists)

**By: William Stallings**

Queuing analysis is one of the most important tools for those involved with computer and network analysis. It can be used to provide approximate answers to a host of questions, such as:

· What happens to file retrieval time when disk I/O utilization goes up?

· Does response time change if both processor speed and the number of users on the system are doubled?

· How many lines should a time-sharing system have on a dial-in rotary?

· How many terminals are needed in an on line inquiry center, and how much idle time will the operators have?

The number of questions that can be addressed with a queuing analysis is endless and touches on virtually every area in computer science. The ability to make such an analysis is an essential tool for those involved in this field. Although the theory of queuing is mathematically complex, the application of queuing theory to the analysis of performance is, in many cases, remarkably straightforward. A knowledge of elementary statistical concepts (means and standard deviations) and a basic understanding of the applicability of queuing theory is all that is required. Armed with these, the analyst can often make a queuing analysis on the back of an envelope using readily available queuing tables, or with the use of simple computer programs that occupy only a few lines of code.

**Link to material:** http://www.electronicsteacher.com/download/queuing-analysis.pdf