Preface

摘要

In a computer system there is a wide spectrum of actions that are to be performed simultaneously in order to maximize throughput and minimize the response time of the system. The diversity of action and reaction which takes place in a large computer system presents serious problems to anyone trying to encompass that entire spectrum. No single theory of optimization-finding the best way to carry out an action to produce a specific result-embraces all the important aspects because each domain of application has unique characteristics that determine the most appropriate approach. There are many problems of long-standing interest which have eluded solution, partly because the problems have not been clearly defined and partly because the most significant parameters to be used in tractable models have not been identified. The eight papers in this issue introduce some important and novel concepts in the analysis and design of computer systems. New viewpoints have been developed for the analysis of significant aspects such as multiprocessing, multiprogramming, system communication, storage management, scheduling, and validation of simulation models. The concepts presented in this group of papers contain numerous warnings and restrictions, which serve to call attention to those aspects of the discussion that must be modified in order to represent in a more realistic manner the physical processes of existing systems. Success in the application of the described models depends on careful formulation by the user and an understanding of the assumptioas and restrictions involved in their use.