On an aggregation method for CPU-disk models

In this paper an approximation method is discussed for solving some special types of CPU-disk models by use of aggregation. The basic model is a closed queuing network model of a computer system. The model consists of several CPU's and disk units. Several types of clients are distinguished. The routing matrix for each type of client, however, restricts the clients to visit only one of the CPU's. The solution method discussed here, is based on the mean value analysis. Numerical experiments are used to show the accuracy of the proposed approximation method. Two types of examples are used here: the aggregation directly applied to the sketched computer model, and used in combination with the parametric analysis of a computer system in a terminal environment