Harold Chestnut

"Models are used essentially for evaluation and prediction purposes as well as for the analysis and study of the different parts of the system so that the systems engineer or designer may arrive at sound engineering decisions regarding the system design."

"I should like to point out two other fields for serious attention by control people. These are (1) The need for optimizing the process of making automatic control, i.e. bridging the gap between theory and practice. (2) The need for working with qualified people in the social, economic, and political fields to help make the net effect of automatic control and automation a cause for hope rather than a reason for fear... The opportunities for a better world at peace make the challenge for using automation for the betterment of man one that is certainly worth working for."

"Finding an alternative to supplement military ways of resolving international conflicts has been taken up by many people skilled in various areas such as political science, economics, social studies, modelling and simulation, intelligence and expert systems, military strategy and weaponry as well as private business and industry."

"The Systems engineering method recognizes each system is an integrated whole even though composed of diverse, specialized structures and sub-functions. It further recognizes that any system has a number of objectives and that the balance between them may differ widely from system to system. The methods seek to optimize the overall system functions according to the weighted objectives and to achieve maximum compatibility of its parts."

"Included in the problems of systems engineering are those of complexity and of choice. Of all the available facts about a system or the needs for a system, which are of most significance for the present circumstances and for their probable future course? How much information is needed and how should it be used to make a satisfactory decision, considering the time and resources available and the purpose to which these data are to be applied? Since most of the means of understanding which we as individuals use, or which are used by the automatic decision-making processes which we employ, are serial processes, we are continually faced with choices of how to divide the jobs to be done and to select an order or an arrangement for systematically handling the abundance of data which are available."

"The process of formulating and structuring a system are important and creative, since they provide and organize the information, which each system. "establishes the number of objectives and the balance between them which will be optimized". Furthermore, they help identify and define the system parts. Furthermore, they help identify and define the system parts which make up its "diverse, specialized structures and subfunctions."

"Simulation is the use of models and/or the actual conditions of either the thing being modeled or the environment in which it operates, with the models or conditions in physical, mathematical, or some other form. The purpose of simulation is to explore the various results which might be obtained from the real system by subjecting the model to representative environments which are equivalent to, or in some way representative of, the situations it is desired to understand or investigate. Simulation may involve system hardware and the actual physical environment, or it may involve mathematical models subjected to mathematical forcing or disturbance functions representative of the systems conditions to be studied."

"A perennial problem of any organization which is involved in systems work of a changing nature is the need for the organization itself to change as it adapts to new opportunities, new objectives, new equipment, and new people."

"[Chestnut] viewed life as one large that needed to be nudged from time to time to keep it running smoothly and on course."

"Chestnuts early control work concerned stability issues in electric power systems. The design and manufacturing of electric power system components - generators, transformers, motors, etc. was a major part of GEs activity then and now. During the Second World War Hal moved into aeronautics and ordinance divisions of the company and remained there until 1956. It was in the late 1940s that he wrote his first book. This pace-setting volume established his reputation as a leading figure in the international control community... Following retirement he concentrated on one of his long time passions in the control field - the potential for control concepts to provide insight into problems of international stability. It seems that his dedication to the use of control concepts in societal problems arose from his success in working with wary representatives from many countries to set up IFAC and with proud representatives from various US engineering societies to set up the AACC."

"On the personal level, Harold Chestnut is remembered as a quiet but persistent man. Once he determined something ought to be done, he worked until he found a way to make it happen. He viewed life as one large control system that needed to be nudged from time to time to keep it running smoothly and on course. He was a devoted family man who enjoyed hiking and sailing with his family, especially at their cottage on Schroon Lake in the Adirondacks. Harold Chestnut will be long remembered for his technical contributions to the field of systems and control, for his leadership in getting people from divers backgrounds to work together, and for setting up institutions that foster ongoing cooperation for the solution of engineering and societal problems."

"Formulating and structuring a system provide methods for relating (1) what the system consists of in the mind of the persons or group desiring it; (2)what it means in terms of the persons or group designing and building it; and (3) in terms of the persons or groups operating, using and servicing it. They provide a set of "reasonable" parts and methods of relating them so that the many persons working on the system can understand the whole in sufficient detail for their purposes, and their particular parts in explicit detail so that they may contribute their best efforts to the extent required. A further purpose of system formulation is to recognize the magnitude of the job, including the possible pitfalls."