Measurements and Approximations to Describe the Offered Traffic and Predict the Average Workload in a Single-Server Queue

We propose measurements and approximations to describe the variability of offered traffic to a queue (i.e., the variability of the arrival process together with the service requirements) and predict the average workload in the queue (which is assumed to have a single server, unlimited waiting space and a work-conserving service discipline). The principal traffic measurement considered is a normalized version of the variance of the total input of work as a function of time, which we call the index of dispersion for work (IDW). Given ample traffic data, the IDW can easily be estimated using sample averages.