Queueing Network Model of Interactive Computing Systems

models for interactive computing systems. One of the earliest analyses was done by Scherr [ 11 for the Com-patible Time-sharing System (CTSS) at M.I.T., Cambridge, Mass. Kleinrock, Chang, Coffman, Muntz, Adiri, Avi-itzhak, and other researchers have also used queue-theoretic models to study CPU scheduling algorithms [2]-[6]. Most of these models are concerned with one system component-the CPU; thus the interrelationships between the CPU and other system components, such as disks, have been ignored. To study an interactive computing system as a whole, a “total system model ” is needed. Using Gordon and Newell’s method [ 71, Moore [ 81 constructed a queueing network model for the Michigan Time-sharing system at the University of Michigan, Ann Arbor. His model consists of peripheral devices as well as the CPU’s, but the effect of memory size on syste