The principal investigator (PI) proposes to explore aspects of non-product-form networks. His approach assumes a more realistic type of model than the so-called product form in which the stationary distribution of queues at network nodes over the entire network can be written as the product of distributions at the individual nodes as if each of the nodes was operation in isolation. If either or both of two assumptions, finite buffer size at each node and exogenous Poisson arrivals and/or exponential service times are eliminated, then the overall queue distribution is no longer of product form and analysis becomes intractable. Professor Tsoucas considers the case when neither assumption holds. He proposes to study the computational problem that results when product form is absent, emphasize parallel asynchronous relaxation procedures, formulate an analog of the "folk" theorem for delays, and consider qualitative properties of the throughput in blocking systems. ***