A simple stochastic model for computer terminal availability

Abstract

Queueing models have been widely applied in the analysis of computer performance, as well as in the study of systems in which service is rendered to human customers by multiple servers. Rarely, however, have queueing theory techniques been applied to the problem of providing computing services to the human beings who require them.We develop a simple queueing model for the availability of computer terminals in an academic computing laboratory, then compare the statistics predicted by the model to those actually observed in several laboratories. Among the statistics considered is the likelihood that a new arrival to the laboratory finds no free terminals, a quantity which is comparable to standard performance measures for communications equipment. The model also generates measures of resource availability which may be analyzed dynamically. Examples of the use of this model are provided.