This paper deals with the problem of modeling computer systems. The most well known computer model is the central server model. The level of detail of this model is insufficient to cope with problems like channel contention. Furthermore, the solution methods to this model are all based on product form assumptions and thus cannot deal with problems like priority queuing and non-exponential workloads. In this paper it is shown. however, that. by using some heuristic extensions of the mean value analysis. one can develop a central server based modeling tool for the performance evaluation of computer systems.
which can cope with these problems.
To reduce the computational complexity of the model. an aggregation method
is introduced. For some aspects of computer performance. like channel contention
in case of disk units operating with rotational position sensing. and disk
seek operations. more detailed models are proposed.