Performance bound hierarchies for queueing networks

In applications of queueing network models to computer system performance prediction, the computational effort required to obtain an exact equilibrium solution of a model may not be justified by the accuracy actually required. In these cases, there is a need for approximation or bounding techniques that can provide the necessary information at reduced cost. This paper presents Performance Bound Hierarchies (PBHs) for single class separable queueing networks consisting of fixed rate and delay service centers. A PBH consists of a hierarchy of upper (pessimistic) or lower (optimistic) bounds on mean system residence time. (The bounds can also be expressed as bounds on system throughput or center utilizations.) Each successive member requires more computational effort, and in the limit, the bounds converge to the exact solution.