2741	 Decomposability Instabilities and Saturation in Multiprogramming Systems	 A step-by-step approach to model the dynamic behavior and evaluate the performance of computing systems is proposed. It is based on a technique of variable aggregation and the concept of nearly decomposable system both borrowed from Econometrics. This approach is taken in order to identify in multiprogramming paging systems i unstable regimes of operations and ii critical computing loads which bring the system into states of saturation. This analysis leads to a more complete definition of the circumstances in which thrashing can set in. multiprogramming paging performance evaluation saturation instabilities thrashing aggregation system levels hierarchy networks of queues
