Confidence intervals on performance estimates

Performance estimates show how a computer system architecture will respond to the load placed upon it. Typical estimates required are response times to particular events, system throughputs and loading levels of CPUs and LANs. The purpose of performance estimation is to reduce risk. It aims to provide the best possible estimate of the system performance as cheaply as possible, and to highlight design weaknesses. This paper places emphasis on the practical applications of performance estimation, focusing on the approach taken early in the system life-cycle. Therefore, it is treated as a costed process, which makes definite recommendations on a design. To understand the approach, some basic concepts behind system modelling are laid down