On Approximate Computer System Models

Abstract

A new treatment of the boundary conditions of diffusionapproximations for interconnected queueing systems is presented. The results have applications to the study of the performance ofmultiple-resource computer systems. In this approximation method,additional equations to represent the behavior of the queues whenthey are empty are introduced. This reduces the dependence of themodel on heavy traffic assumptions and yields certain results whichwould be expected from queueing or renewal theory. The accuracy ofthe approach is evaluated by comparison with certain known exact ornumerical results. © 1975, ACM. All rights reserved.