Systems engineers

"Humanity faces the most complex task of its history so far. Stated in a solution-oriented way, it is necessary gradually to reorganize this planet at two levels. One must deal with the competing necessities of biosphere and mankind with all their environmental and climatic consequences. On the other level, it is necessary to resolve the demands of competing nations and worlds within mankind's hierarchy of socioeconomic developmental levels and the "Christmas tree" of sociopolitical, ideological, and military consequences."

"The economic function of space industrialization is to generate jobs on Earth, not in space."

"If God wanted man to become a spacefaring species, he would have given man a moon."

"Since it can be argued that both science and engineering are concerned with the study of real systems and their behavior, it follows that a general theory should be concerned with the study of general systems... It suffices for the present discussion to consider a general system as an abstract analogue or model of a class of real systems. General systems theory is then a theory of general models."

"General systems theory deals with the most fundamental concepts and aspects of systems. Many theories dealing with more specific types of systems (e.g., dynamical systems, automata, control systems, game-theoretic systems, among many others) have been under development for quite some time. General systems theory is concerned with the basic issues common to all these specialized treatments. Also, for truly complex phenomena, such as those found predominantly in the social and biological sciences, the specialized descriptions used in classical theories (which are based on special mathematical structures such as differential or difference equations, numerical or abstract algebras, etc.) do not adequately and properly represent the actual events. Either because of this inadequate match between the events and types of descriptions available or because of the pure lack of knowledge, for many truly complex problems one can give only the most general statements, which are qualitative and too often even only verbal. General systems theory is aimed at providing a description and explanation for such complex phenomena."

"The concept of the “organic growth” of mankind, as we have proposed in this report, is intended as a contribution toward achieving that end. Were mankind to embark on a path of organic growth, the world would emerge as a system of interdependent and harmonious parts, each making its own unique contributions, be it in economics, resources, or culture. ... Such an approach must start from and preserve the world’s regional diversity. Paths of development, region-specific rather than based on narrow national interests, must be designed to lead to a sustainable balance between the interdependent world-regions and to global harmony – that is, to mankind’s growth as an “organic entity” from its present barely embryonic state."

"There is a much more subtle and completely novel threat to man's survival that looms, every year more menacingly, beside that of an atomic holocaust; the cluster of world-wide problems - not only material in nature - growing at an incredible speed when viewed in historical perspective, and called by The Club of Rome the "problématique humaine. In fact, we believe that even without the atomic world war, human existence as we know it is threatened if no way can be found to resolve this crisis syndrome."

"In Nature organic growth proceeds according to a “master plan,” a “blueprint.” According to this master plan diversification among cells is determined by the requirements of the various organs; the size and shape of the organs and, therefore, their growth processes are determined by their function, which in turn depends on the needs of the whole organism. Such a “master plan” is missing from the process of growth and development of the world system... The masterplan has yet to evolve through the existence of options by people who constitute the world-system."

"There is no such concept as one limit for the entice system: rather different parts of the system face different limits at different times with the traumatic experiences for the entire system depending on the interrelationship of the constituent parts - the collapse, if it occurs, would he regional rather than global, even though the entire global system would be affected."

"Isn't it legitimate to ask, as representatives of the developing countries, whether there should be maximum limits consumption...?"

"To grow or not to grow is neither a well-defined nor a relevant question until the location, sense, and subject of growing and the growth process itself are defined"

"[Another significant aspect of the concept of growth is the distinction that Mesarovic and Pestel draw between "undifferentiated" and "organic" growth. The former type of growth, according to these authors, consists of mere replication of cells by cellular division, usually expotentially, with an increase in quantity alone. The latter type of growth] involves a process of differentiation, which means that various groups of cells begin to differ in structure and function... During and after differentiation the number of cells can still increase, and the organs grow in size, but while some organs grow, others might celine."

"General systems theory is considered as a formal theory (Mesarovic, Wymore), a methodology (Ashby, Klir), a way of thinking (Bertalanffy, Churchman), a way of looking at the world (Weinberg), a search for an optimal simplification (Ashby, Weinberg), didactic method (Boulding, Klir, Weinberg), metalanguage (Logren), and profession (Klir)."

"We have no aces to what the world is, to ontology, only to descriptions of the world... that is to say, epistemology... We should never say something in the world: 'it is a system'; only: "it may be described as a system'."

"We reduce the complexity of the variety of the world in experiments whose results are validated by their repeatability, and we may build knowledge by the refutation of hypotheses."

"The concept of action research arises in the behavioural sciences and is obviously applicable to an examination of human activity systems carried out through the process of attempting to solve problems. This core is the idea that the researcher does not remain an observer outside the subject of investigation but becomes a participant in the relevant human group. The researcher becomes a participant in the action, and the process of change itself becomes the subject of research. In action research the roles of researcher and subject are obviously not fixed: the roles of the subject and the practitioner are sometimes switched: the subjects become researchers... and researchers become men of action."

"A methodology will lack the precision of a technique but will be a firmer guide to action than a philosophy. Where a technique tells you 'how' and a philosophy tells you 'what', a methodology will contain elements of both 'what' and 'how'."

"In a certain sense human activity systems do not exist, only perceptions of them exist, perceptions which are associated with specific Ws."

"The core of a root definition of a system will be a transformation process (T), the means by which defined inputs are transformed into defined outputs. The transformation will include the direct object of the main activity verbs subsequently required to describe the system."

"Making drawings to indicate the many elements in any human situation is something which has characterized SSM from the start. Its rationale lies in the fact that the complexity of human affairs is always a complexity of multiple interacting relationships; and pictures are a better medium than linear prose for expressing relationships. Pictures can be taken in as a whole and help to encourage holistic rather than reductionist thinking about a situation."

"Cursory inspection of the world suggests it is a giant complex with dense connections between its parts. We cannot cope with it in that form and are forced to reduce it to some separate areas which we can examine separately'. .."

"In an unrestricted science such as biology or geology, the effects under study are so complex that designed experiments with controls are often not possible. Quantitative models are more vulnerable and the chance of unknown factors dominating the observations is much greater."

"A root definition describing a notional system chosen for its relevance to what the investigator and/or people in the problem situation perceive as matters of contention."

"Systems thinking, as written about and practiced by Russell Ackoff, C. West Churchman, Peter Checkland and others, contained within it many of the impulses that motivate the application of design ideas to strategy, organization, society, and management. Ideas such as engaging a broad set of stakeholders, moving beyond simple metrics and calculations, considering idealized options and using scenarios to explore them, shifting boundaries to reframe problems, iteration, the liberal use of diagrams and rich pictures, and tirelessly searching for a better set of alternatives were all there. If the business and management community had bought it, we would not be having the many discussions about design, design thinking, and expanding management education to engage the intuitive, to embrace values, to look beyond available choices."

"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."

"Engineers should press forward with development to meet the diversified needs of people."

"Those of us concerned with developing new technology should consider ourselves to have a major undertaking to try to meet the expanding needs of the increasing number of people in the world with its finite resources and environments constraints."

"The term closed loop-learning process refers to the idea that one learns by determining what s desired and comparing what is actually taking place as measured at the process and feedback for comparison. The difference between what is desired and what is taking place provides an error indication which is used to develop a signal to the process being controlled."

"Although control principles are not customarily associated with international relations, there may be some significant advantages in seeing how international relations may benefit by suitable use of control concepts and methods. Over the years, control engineers and scientists have learned how to use information processing and equipment, along with energy and materials to improve the performance of various systems."

"As control engineers and scientists, we have greatly altered the way people and nations live and interact with one another. We have helped to create a world in which people live longer, enjoy better health, are better educated, and can travel and communicate over greater distances. But the systems that provide these better lives are fragile systems subject to unpredictable failures and possible destruction. We have also helped to create a world in which international relations are such that the very civilizations we have helped to build over centuries can be destroyed in a matter of hours."

"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."

"In a society which is producing more people, more materials, more things, and more information than ever before, systems engineering is indispensable in meeting the challenge of complexity."

"Characteristic of our times are the concepts of complexity, growth and change."

"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."

"A model is a qualitative or quantitative representation of a process or endeavor that shows the effects of those factors which are significant for the purposes being considered. A model may be pictorial, descriptive, qualitative, or generally approximate in nature; or it may be mathematical and quantitative in nature and reasonably precise. It is important that effective means for modeling be understood such as analog, stochastic, procedural, scheduling, flow chart, schematic, and block diagrams."

"As is used in connection with systems engineering, a model is a qualitative or quantitative representation of a process or endeavor that shows the effects of those factors which are significant for the purposes being considered. Modeling is the process of making a model. Although the model may not represent the actual phenomenon in all respects, it does describe the essential inputs, outputs, and internal characteristics, as well as provide an indication of environmental conditions similar to those of actual equipment."

"A model may be pictorial, descriptive, qualitative, or generally approximate in nature, or it may be mathematical and quantitative in nature and reasonably precise."

"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."

"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."

"Knowledge about the process being modeled starts fairly low, then increases as understanding is obtained and tapers off to a high value at the end."

"In a world in which training and functions of individuals and groups are growing more and more specialized the number of ways to accomplish any particular result increasing. Different design, different facilities, different equipment, different methods, and different organizational means are available to meet the needs of man. It is highly desirable that we have trained persons look at these varied possibilities to compare their effectiveness, and to point the way to sound engineering decisions. Systems Engineering Methods is directed towards the development of a broad systems engineering approach to help such people improve their decision-making capability. Although the emphasis is on engineering, the systems approach can also has validity for many other areas in which emphasis may be social, economic, or political."

"Each system is unique. However, by capitalizing on similarities we can reduce the time, effort, and cost for some or all of them, and thus the quest for formalized design methods becomes more attractive."

"The concept of a system is not a simple or unique one. There are many different kinds of systems, and different systems may be organized and operated in different ways. As individuals we all belong to some social system, we participate in an economic system, we are the product of several educational systems, and we are members of one or more family systems. In a similar fashion, the equipment of which physical systems are made may be members of many other systems, such as electrical, mechanical, sensing, actuating, energy, materials, and/or information systems. One of the challenges to the person who engineers a system is to find the many alternative ways in which the function, the operation, and/or the equipment of concern and interest may be considered, understood, and made to perform most effectively."

"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."

"System costs can be considered in many different ways. For example, the cost for making the system and the cost for operating it may be used as a basic for judging the total cost. The total cost may also be arrived at in another fashion, as, for example, the sum of the fixed cost, variable cost, past investment and other charges. Furthermore, in many cases where systems engineering is required several time phases are involved for which the cost factors may be significant, such as the study phase, the breadboard phase, the prototype phase, and the production phase."

"In addition to technical problems, systems also have organizational and logistical problems. Many different people may be involved over a wide physical or geographic coverage and over a long period of time. Many may work for different companies or organizations with different rules and methods of operating. Very many data and much knowledge are involved. The organizational problem concerns itself with the question of how all these people can work together most effectively for the common purpose."

"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."

"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."

"Formulating consists of determining the system inputs, outputs, requirements, objectives, constraints. Structuring the system provides one or more methods of organizing the solution, the method of operation, the selection of parts, and the nature of their performance requirements. It is evident that the processes of formulating a system and structuring it are strongly related."

"From a pessimistic viewpoint, it can be stated that there is no good general way of structuring a system. However, from an optimistic point of view one can say that a number of good ways of structuring systems exist and that some are better than others for any particular system. In this and the following sections, there will be a presentation of a number of structuring approaches that have merit and have been employed successfully, including functional structuring, equipment structuring, and use of various coordinate systems."

"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."

"The book [Systems Engineering Methods]... covers (1) the environment for systems engineering, (2) system organization, scheduling, and record-keeping, (3) formulating and structuring the system, (4) factors for judging the value of a system, (5) cost-estimation and cost-effectiveness analysis, (6) operational meanings and effects of time, and PERT-type network analysis, (7) reliability, and (8) future opportunities for systems engineering. It is believed that few subjects are covered deeply enough to make the book useful as a text or self-study guide without considerable supplementary reading."

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

"Chestnut's 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 GE's 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."

"Systems engineering is most effectively conceived of as a process that starts with the detection of a problem and continues through problem definition, planning and designing of a system, manufacturing or other implementing section, its use, and finally on to its obsolescence. Further, Systems engineering is not a matter of tools alone; It is a careful coordination of process, tools and people."

"For any given set of objects it is impossible to say that no interrelationships exist."

"It is time to employ fractal geometry and its associated subjects of chaos and nonlinear dynamics to study systems engineering methodology (SEM). Systematic codification of the former is barely 15 years old, while codification of the latter began 45 years ago... Fractal geometry and chaos theory can convey a new level of understanding to systems engineering and make it more effective"

"The plan of the present paper is to discuss properties of systems more or less abstractly; that is to define system and to describe the properties that are common to many systems and which serve to characterize them all."

"Unfortunately, the word "system" has many colloquial meanings, some of which have no place in scientific discussion. In order to exclude such meanings, and at the same time provide a starting point for exposition we state the following definition: A system is a set of objects together with relationships between the objects and between their attributes. Our definition does imply of course that a system has properties, functions or purposes distinct from its constituent objects, relationships and attributes."

"For any given system, the environment is the set of all objects whose behaviour is influenced by the behaviour of the primary system, and those objects whose behaviour influences the behavior of the primary system."

"In our definition of system we noted that all systems have interrelationships between objects and between their attributes. If every part of the system is so related to every other part that any change in one aspect results in dynamic changes in all other parts of the total system, the system is said to behave as a whole or coherently. At the other extreme is a set of parts that are completely unrelated: that is, a change in each part depends only on that part alone. The variation in the set is the physical sum of the variations of the parts. Such behavior is called independent or physical summativity."

"Synthesis of systems is much more difficult. Here science and engineering begin to take on aspects of art. A systems designer or planner not only must construct systems that work harmoniously individually and in tandem, he must also know a lot about the environment that the system is intended to match. Consideration of environmental factors requires foresight and experience; no one can ever foresee all the variables of importance and a choice of which to include is often a difficult one to make."

"It is hard to say whether increasing complexity is the cause or the effect of man's effort to cope with his expanding environment. In either case a central feature of the trend has been the development of large and very complex systems which tie together modern society. These systems include abstract or non-physical systems, such as government and the economic system. They also include large physical systems like pipe line and power distribution systems, transportation and electrical communication systems. The growth of these systems has increased the need not only for over-all planning, but also for long-range development of the systems. This need has induced increased interest in the methods by which efficient planning and design can be accomplished in complex situations where no one scientific discipline can account for all the factors. Two similar disciplines which emerged about the time of World War II to cope with these problems are called systems engineering and operations research."

"For a given system, the environment is the set of all objects outside the system: (1) a change in whose attributes affect the system and (2) whose attributes are changed by the behavior of the system."

"Every part of the system is so related to every other part that a change in a particular part causes a changes in all other parts and in the total system"

"A system is a set of objects with relationships between the … in may be described generally as a complex of elements or components directly or indirectly related in a causal network, … Also, we are mainly interested in systems within which some process is continually going on, including an interchange with an environment across the boundary. It is generally agreed that when we deal with the more open system with a highly flexible structure, the distinction between the boundaries and the environment becomes a more and more arbitrary matter, dependent upon the purpose of the observer."

"God made Homo sapiens a problem-solving creature. The trouble is that He gave us too many resources: too many languages, too many phases of life, too many levels of complexity, too many ways to solve problems, too many contexts in which to solve them, and too many values to balance. First came the law, accounting, and history which looks backward in time for their values and decision-making criteria, but their paradigm (casuistry) cannot look forward to predict future consequences. Casuistry is overly rigid and does not account for statistical phenomena. To look forward man used two thousand years to evolve scientific method - which can predict the future when it discovers the laws of nature. In parallel, man evolved engineering, and later, systems engineering, which also anticipates future conditions. It took man to the moon, but it often did, and does, a poor job of understanding social systems, and also often ignores the secondary effects of its artifacts on the environment. Environmental impact analysis was promoted by governments to patch over the weakness of engineering - with modest success - and it does not ignore history; but by not integrating with system design, it is also an incomplete philosophy. System design and architecture, or simply design, like science and engineering is forward-looking, and provides man with comforts and conveniences - if someone will tell them what problems to solve, and which requirements to meet. It rarely collects wisdom from the backward-looking methodologies, often overlooks ordinary operating problems in designing its artifacts, whether autos or buildings, and often ignores the principles of good teamwork."

"The operational sciences hoped to nourish business management, which however largely ignored them, and the latter continues to be undernourished by the business schools which are fairly broad but shallow everywhere. By over focus on short-range financial values, business management in the United States has lost a dozen major markets to the Japanese, added pollution in all its forms, and enriched itself out of all proportion to its value as just one factor of production. Action science, developed by the social sciences over many years in relative isolation from the applied physical sciences, and which might otherwise have humanized them and made engineering more productive, was doomed to fail by being on one end of the two-culture problem wherein science and the humanities do not even speak the same language. I could go on listing a few dozen paradigms: art, law, computer software design, medicine, politics, and architecture, each addressed to a certain context, level, or phase, each good in itself, but each limited to the fields of its origin and its purposes. The methodological problem is the same as if, in designing any large system, each subsystem designer were left to design each subsystem to the best requirements he knew. The overall requirement might not be met; overall harmony could not be achieved, and conflict could ensue to cause failure at the system level. What is envisioned is a new synthesis, a unified, efficient, systems methodology (SM): a multiphase, multi-level, multi-paradigmatic creative problem-solving process for use by individuals, by small groups, by large multi-disciplinary teams, or by teams of teams. It satisfies human needs in seeking value truths by matching the properties of wanted systems, and their parts, to perform harmoniously with their full environments, over their entire life cycles"

"Has mankind evolved to a point that there exists, or that with creative additions and re-combinations of modest proportions, there can be shown to be available, a common systems methodology, in terms of which we can conceive of, plan, design, construct, and use systems (procedures, machines, teams of people) of any arbitrary type in the service of mankind, and with low rates of failure?"

"History becomes one model needed to give a rounded view of our subject within the philosophy of hierarchical holographic modeling, defined as using a family of models at several levels to seek understanding of diverse aspects of a subject and thus comprehend the whole."

"The basic functional elements of any automatic control system: sensing, converting, storing, communicating, computing, programming, regulating, actuating, and display (Chestnut, 1967). Many kinds of systems in being, speculated about, or even intuited, ranging from computers, most factory processes, communication systems, road networks, automatic farms, etc., have structures which can be invoked as zero-order matches to proposed sets of throughputs, especially for single- thread designs. This method of structuring is related closely to analogical design, of which a special form is called synectics."

"A.D. Hall's (1962) classic account of the methodology was based on his experience with the Bell Telephone Laboratories. Hall sees systems as existing in hierarchies. In systems engineering, plans to achieve a general objective must similarly be arranged in a hierarchy, with the systems engineer ensuring the internal consistency and integration of the plans, The methodology itself ensures the optimization of the system of concern with respect to its objectives. This requires a number of steps, the most important being problem definition, choosing objectives, systems synthesis, systems analysis, systems selection, system development, and current engineering. With Hall, the system of concern is usually a physical entity."

"The motives for conceiving modern systems engineering are to be found, at least in part, in past disasters. Arthur D. Hall III [1989] cites: the chemical plant leakage in Bhopal (1986); the explosion of the NASA Challenger space shuttle (1986) and the Apollo fire (1967); the sinking of the Titanic (1912); the nuclear explosion in Chernobyl (1986) and the disaster at Three Mile Island power plant (1979). He cites, too, the capture of markets by Japan from the U.S., the decline in US productivity and the failure of the US secondary school system. He identifies the millions of people dying of starvation every year while other nations stockpile surplus food, medical disasters such as heart disease, while governments subsidize grains used to produce high cholesterol meat, milk and eggs; and many more. One implication is clear: systems engineering faces challenges well beyond the sphere of engineering."

"Arthur D. Hall (1962) identified five traits of the ideal systems engineer and these certainly still stand today; these traits are: (1) an affinity for the systems … (2) faculty of judgment, (3) creativity, (4) facility in human relations, and (5) a for expression. The specific role of the systems engineer has traditionally been rather inwardly focused, with considerations to environment and external systems. In this broader field of Engineering Systems, the systems engineering practitioners may need to re-evaluate their roles and responsibilities in the overall systems effort."

"The fellow who is able to get the grants and contracts is the fellow who gets the doctoral students. Each student publishes two or three papers on his thesis, in each of which he cites his professor's work. Then he goes on and does his own subsequent work, in which, of course, he cites those thesis papers which were coauthorised by his professor."

"The lack of formal definition does not prevent us from noting the characteristics which are frequently present in large scale systems. Each such system has a certain integrity. It may or may not be rigidly controlled from some central point, but in every case, all the parts of the system have some common purpose; in some sense, they all contribute to the production of a single set of optimum outputs from the given set of inputs, with respect to some appropriate measure of effectiveness."

"A new concept and a new method were needed. The concept from the engineering standpoint is the evolution of the engineering scientist, i.e., the scientific generalist who maintains a broad outlook. The method is that of the team approach. On large-scale-system problems, teams of scientists and engineers, generalists as well as specialists, exert their joint efforts to find a solution and physically realize it. We are led to the concept of the system-design team, a small group of engineers or scientists, to lead a large project and organize the system effort. Such men have been variously called engineering scientists, system engineers, system analysts, or large-scale-system designers. The technique has been variously called the systems approach or the team development method. It is toward this man and his teammates that these discussions are directed. With the realization that not enough can be learned in all the required fields to make him a specialist, enough is introduced to make him aware of the language and problems of the specialist. This generalist is a new quantity in the engineering world, and his education must be begun."

"There are four distinct bases on which a system-design book might be organized. First are the chronological phases through which the system-design effort passes, such as organization and preliminary design. Second are the logical steps such as analysis of the single thread (operation on a single input) and high traffic (methods of handling multiplex inputs). Third are the parts of the system, such as communications and displays. Fourth are the tools of system design, such as information theory and queueing theory."

"[Systems should be classified] on the basis of the types of inputs with which they must cope."

"[This set of inputs [can be defined] as 1) input which is always the same or is of many types, 2) input which occurs periodically (or very infrequently), and 3) input which does or does not seek to destroy the system. Their rationale for developing the classification was to aid in the definition of steps to be followed in order to find the] solution of the problem of a large-scale or complex system."

"Every large-scale system is an . The automatic factory, the vehicular-traffic system, any military system- in the design of all these systems, primary attention should be given to the flow of information about the elements of the system."

"Management has a design and operation function, as does engineering. The design is usually done under the heading of organization. It should be noted first that the performance of a group of people is a strong function of the capabilities of the individuals and a rather weak function of the way they are organized. That is, good people do a fairly good job under almost any organization and a somewhat better one when the organization is good. Poor talent does a poor job with a bad organization, but it is still a poor job no matter what the organization. Repeated reorganizations are noted in groups of individuals poorly suited to their function, though no amount of good organization will give good performance. The best architectural design fails with poor bricks and mortar. But the payoff from good organization with good people is worthwhile."

"In April of 1959, ten of this country's leading scholars forgathered on the campus of Purdue University to discuss the nature of information and the nature of decision... What interests do these men have in common?... To answer these questions it is necessary to view the changing aspect of the scientific approach to epistemology, and the striking progress which has been wrought in the very recent past. The decade from 1940 to 1950 witnessed the operation of the first stored- program digital computer. The concept of information was quantified, and mathematical theories were developed for communication (Shannon) and decision (Wald). Known mathematical techniques were applied to new and important fields, as the techniques of complex- variable theory to the analysis of feedback systems and the techniques of matrix theory to the analysis of systems under multiple linear constraints. The word "cybernetics" was coined, and with it came the realization of the many analogies between control and communication in men and in automata. New terms like "operations research" and "system engineering" were introduced; despite their occasional use by charlatans, they have signified enormous progress in the solution of exceedingly complex problems, through the application of quantitative ness and objectivity."

"At this time it is difficult to put one's finger on any single contribution in the decade 1950 - 1960 which is comparable to those above, and yet progress has probably been even greater. From the point of view of an educator, one cannot overlook the wide distribution which has been given to these ideas. There has been remarkable progress from analysis to synthesis, always a sign of maturity in a field of analytic endeavour. There has been consolidation, for example in the establishment of a more rigorous basis for information theory; there has been unification, for example in the demonstration of the formal similarity between game theory and ; there has been application to mathematically more difficult situations, for example nonlinear servo systems and information channels with memory; there has been implementation, as in commercially available computers which by any reasonable measure are hun- dreds of times more powerful than the primitive devices of 1950; there has been de-limitation of the boundaries of many of these fields."

"We have discovered in this past decade that thinking, and decision, are not solely the province of the metaphysicist, but are appropriate subjects for scientific inquiry."

"We assert that it is possible to describe analytically any human function which can be reasonably defined in objective terms and we specifically include in such functions "thinking" insofar as that term is definable. If by "thinking" one means being able to do arithmetic, or play a good game of chess, or learn from experience, or make optimal decisions in exceedingly complex situations, then we assert that thinking can be described analytically. And there are two important corollaries: if It can be described analytically, it can be simulated; and if it can be simulated, it can be performed mechanically."

"[There is a] basic problem … of building a mathematical model of thought processes, and in particular of those aspects of thought which are concerned with information and decision processes. The perceptron is one type of model -- a set of memory devices connected in random fashion-- which has not yet achieved useful results but certainly seems to be a promising approach. The self-adaptive feedback control system which goes beyond the normal servo function of controlling its output, and in addition controls the parameters by which it controls its output is another which has already achieved pragmatic results in equipment control. It may be that the question of self-adaptation is a key to the whole question of how the human functions in a decisioning situation. For in many cases the ability of the human mind to adapt itself to a changing and complex environment is beyond our present aims in model construction."

"Sometimes it is more difficult to formulate the criterion for a problem than to state the question itself."

"Everyone knows what engineering is. All that's left is to define systems, and I'm not fool enough to do that."

"The purpose and real value of systems engineering is... to keep going around the loop; find inadequacies and make improvements."

"Mathematicians are there to find the constraints and to eliminate those things that aren't constraints... I know this will surprise many of you, but they are useful!"

"Scientists possess healthy skepticism. They realize that you've got to know the answer before you measure it."

"The ideal system engineer is an engineer thoroughly versed in his field but conversant with and knowledgeable of other fields. You have to have the capability and desire to become a 'six-month expert'... You've got to want to become a generalist, too."

"The conclusions of most good operations research studies are obvious."

"If the assumptions are wrong, the conclusions aren't likely to be very good."

"There comes a time when one must stop suggesting and evaluating new solutions, and get on with the job of analyzing and implementing one pretty good solution."

"Sometimes, where a complex problem can be illuminated by many tools, one can be forgiven for applying the one he knows best."

"Most accidents in well-designed systems involve two or more events of low probability occurring in the worst possible combination."

"The pressure to generate the ideas and methods attributed to Systems Engineering stems directly from the needs of 20th century society. As our frontiers have disappeared, man has turned to technology to furnish the "good life" in a rapidly shrinking, crowded world. Our interdependence upon one another has increased in direct proportion to the population increase. The race to maintain or improve the operating efficiency of society has required that the systems and mechanisms that serve the society also become increasingly complex and interdependent. Goode and Machal have provided statistics to illustrate the above. They note that the world population increased from 800 million in 1750, to 1200 million in 1850, and 2400 million in 1950. Maximum transportation speeds went from 40 mph in 1850, and 100 mph in 1900, to commercial transport speed of 350 mph in 1950 and supersonic transport planes of over 1200 mph in the 1960's. Our communication systems are a good indication of increasing complexity. U.S. telephones jumped from 350,000 in 1900, to 55 million in 1955."

"At an age when many people consider retiring, Robert E. Machol stopped teaching at Northwestern University and started a new career as chief scientist for the Federal Aviation Administration. There, while in his 70s, he predicted "catastrophe" after studying the turbulence created by the jet engines of 757 airplanes--work that predicted fatal crashes and eventually led to a change in federal aviation policy... "I was the first guy within the agency who got up and said, `We're likely to have a catastrophe, a real catastrophe … if we don't do something," Mr. Machol told the Los Angeles Times in 1994. Eventually, the agency ordered landing aircraft to maintain a greater distance behind 757s to avoid the jet's dangerous "wake vortex." But the policy change came only after crashes in Billings, Mont., and Santa Ana, Calif., that killed 13 people."

"Bob Machol's life involved a number of strands — aviation, scientific writing, systems engineering, chemistry, research, applying OR to sports, computing and mushrooms — that intertwined over the years. Consider his involvement with aviation. It started in 1940 when, fresh out of Harvard, Bob enlisted in the Marines, intent on becoming an aviator. Although Bob didn't earn his pilot's wings, he did emerge from World War II holding the rank of lieutenant commander. Following the war, Bob became involved with research organizations (the Operations Evaluation Group and the University of Michigan's Willow Run Laboratories) that were looking for improved ways of defending the United States against air attack. This work led to Bob's groundbreaking book, "Systems Engineering," co-authored with the late Harry H. Goode."

"I recount this as it reminds me of some of the lessons Bob preached and practiced throughout his professional career:"

"I had professor Machol at Kellogg in 1985 for Operations. Professor Machol was intimidating. Rumor around the class was that he had been in charge of logistics for the U.S. Navy in the Pacific theatre during WWII. He was teaching EOQ modeling in one early class, leading me to pose a question, ‘Professor Machol, would it not make sense to do … for the sake of consistency’. His reply is oh so memorable almost 40 years ago.. “Mr. Clark, consistency is the bugaboo of small minds” (ouch!). No doubt relative to this giant, my mind was and remains small indeed!"

"Feedback: It is the fundamental principle that underlies all self-regulating systems, not only machines but also the processes of life and the tides of human affairs."

"Already well known to engineers all over the world as a pioneer in the development of automatic control, it may well turn out that Gordon Brown will make a still deeper mark on the engineering development of this century."

"He is transported to that curious world of decibels and negative frequencies where filter experts live."

"Methods by which engineers stabilise their mechanisms suggest analogous possibilities for stabilising economic systems."

"When beliefs need some modification, We make it with much trepidation, For our world is then new, And things seem all askew, 'til we're used to the new formulation."

"The topic that I have attempted to explore is the usefulness of these notions of the engineer, about feeds-back, harmonic components and the like, in application to the analogous problems of economic fluctuation and economic regulation."

"The analysis of engineering systems and the understanding of economic structure have advanced since then, and the time is now more ripe to bring these topics into a potentially fruitful marriage."

"The ‘theory of control systems’ in engineering is now a well-developed subject, making use of some remarkably powerful concepts and methods of analysis, especially in relation to problems of stabilization and the prevention of unwanted oscillations."

"Consideration of a further possibility, namely that of constructing physical systems that are analogues of the economic system, and of observing and recording their behaviour."

"An economic system is not a linear system, and... this fact stands in the way of the determination of the parameters of the system by methods that presume linearity, and... it introduces great difficulties in the extrapolation from past behaviour for purposes of prediction."

"The nature of the instability of an unregulated free-enterprise system is only now beginning to be clearly understood. Perhaps the degree of understanding already attained ensures that the grosser shortcomings have gone for ever, and to that extent the conflict between Capitalism and Communism is about issues that belong to the past. It may now be too late. The gods must smile to note how different the state of the world might have been if the progress of economic thought of the last twenty years had been advanced by even ten years. The possibility of a stable economic life with full utilization of our resources is still not sufficiently assured, and it is extremely important that it should be so assured, and that the whole world should accept this as a fact. The work that is being done in econometrics is massive, and undaunted by mathematical difficulties, but it appears, at any rate as viewed from outside, to be unclear as to its aim."

"The striking parallel between the economic models that are currently under discussion and some engineering systems suggests the hope that in some way the rapid progress in the development of the theory and practice of automatic control in the world of engineering may contribute to the solution of the economic problems."

"It is possible that the major collaboration between economists and engineers is still to come, in the greater use of physical analogues and computers of the analogue type to avoid the difficulties of calculation. Apart from their major use as possible tools for economic regulation, physical analogues have a subsidiary use, for there are students of economics, as there are many students of engineering, who can better understand the significance of the somewhat formidable mathematics that tends to be used in this field, if they can first acquaint themselves with the types of behaviour in question as exhibited by physical objects that can be seen, felt, handled and experimented with. It may also be suggested that economists may find that what they have to say about economic policy will be very readily assimilated by one group of attentive pupils, namely the scientists, engineers and technicians of industry, if explanatory notions can be drawn from the theory of automatic control, which is now part of a normal engineering education. The aim of this essay has been to give explanations of system behaviour, and some approaches to its analysis, using geometrical construction and physical analogy where possible to clarify the implications of the more usual formal algebraic approach."

"The separate excitation of the dynamo corresponds with the independently determined investment in the economic model, and the total excitation with income. Perhaps in this electrical age, the conventional metaphor of ‘priming the pump’ might be dropped in favour of ‘exciting the dynamo’."

"Actual economic systems are constantly subjected to change and disturbances, which would result in irregularity."

"The writer, who as an engineer has spent most of his life in factories, is inclined to look at the basis for investment from a technological point of view... Consider … the class of industrial investments only... The situation is one of entrepreneurs and boards of directors considering, from time to time, various ’possibilities of investment’, such as extra lathes or looms, an extension to a factory, a venture in some completely new product, and so on. It is helpful to think of these ’opportunities for investment’ as existing, in a given situation, in great number and variety, whether they are at that moment under active consideration or not. When any such possibility is considered it is assessed in respect of ’expected profitability’. One may conveniently think of all possibilities of investment as ’quanta’ that can be placed in a schedule of small ranges of expected profitability according to these assessments. The placement of a given ’opportunity for investment’ on this schedule has some ’margin of uncertainty’ (a curious analogy with the case of the quanta of physics)."

"Simulators set up the required system of interdependences, usually between electrical potentials or voltages as variables, by means of valve-amplifiers and electrical networks. Since the voltage across a capacitance is proportional to the integral of a current, that across an inductance to the first derivative of a current, and that across a resistor to the current itself, it is possible to arrange a network of electrical elements, with amplifiers and feeds-back where necessary, so that a given linear differential equation is caused to relate an ’output’ voltage to an ’input’ voltage. Thus a given linear system of interdependences can be simulated, either directly or in any convenient transformation. If non-linear relationships are required there is no universally applicable simple device, but there do exist a great variety of non-linear elements with non-linear characteristics that are known and to some extent; adjustable. These include non-linear resistors... and the characteristic curves of thermionic valves, of rectifiers and discharge vessels and of magnetic materials. Limits may be set by the use of neon tubes that become conducting when a certain voltage is exceeded, or by relays, and so on"

"Once a full-employment policy has been adopted... the economic ’system’ just on that account is significantly different. Its equilibrium position has been shifted to a rising curve of trend close to and following the employment ceiling. The conditions of stability about this new level are radically different because the region of operation is now within the less flexible and sharply non-linear range of employment saturation"

"There are certain formal similarities between the problems of devising policies for economic stabilisation and those of designing automatic control systems. Methods have recently been developed by engineers for analysing the dynamic properties of quite complex models... [which] can also be used for the analysis of dynamic process models in economics... Professor Tustin’s book contains material of fundamental importance for all who are engaged in either theoretical or empirical studies of dynamic processes in economics. It throws new light on the possibilities and the difficulties of quantitative research in this field."

"Interest in the human-operator problem was stimulated by Prof. Arnold Tustin of the University of Birmingham, England, who suggested the application of the delay-line synthesizer to the study of some tracking records which he had brought with him from England. His experimental setup from which data were obtained consisted of a movable handle unit whose output was integrated once and then made to position a mechanical pointer. A second pointer, located next to the handle-driven pointer, was given an input motion consisting of a number of sinusoidal components of a nature sufficiently involved to prevent anticipation by an operator. The operator, upon noticing an error or difference between the two pointers, was required to move the handle in such a way as to reduce this error to a minimum value..."

"Two kinds of self-controlling machines exist: the regulators whose effect has a fixed value and the Servo-mechanisms whose effect has a value depending on the value of a variable which is the “control.” The idea is simple and reveals itself to be accurate. We have found it confirmed by the technical authority, Prof. Arnold Tustin, of the University of Birmingham, who during the war elaborated a system for the movement of gun turrets and naval guns. According to him, if a machine were entrusted with driving a car, it would be a regulator on a straight road and a servo on a winding one."

"During the early phase of World War II, Britain was challenged to refine the understanding of human control of tanks and aircraft. The first engineering-oriented manual control models were probably those of Prof. Arnold Tustin in the United Kingdom applied to tank-control, followed closely by models by J.P. North of Boulton- Paul Aircraft Co."

"Arnold Tustin (1899–1994) introduced the that bears his name to the control community to relate discrete-time and continuous-time systems."

"Arnold Tustin is best known for his contributions to control theory and its application to electrical machines. However, his interests were much wider than electrical engineering, for he was a polymath who brought a systems approach to each of the many areas that he investigated. In the modern jargon he thought ‘outside the box’ and in doing so championed the use of control systems theory beyond its traditional limits. His impact was such that, in addition to his engineering contributions, he is well known for his systems treatment of economics and to a lesser extent... biology."

"System engineering is the art and science of creating effective systems, using whole system, whole life principles."

"A system is an open set of complementary, interacting parts, with properties, capabilities and behaviours of the set emerging both from the parts and from their interactions to synthesize a unified whole."

"The Holy Grail of systems engineering, a generic systems methodology has been the subject of the author’s ongoing research for over 20 years."

"The real world is made from open, interacting systems, behaving chaotically."

"The world about us can be looked at in a variety of ways. One way is to see the world as made up from many interacting systems: weather, societal, economic, ecological, floral, faunal, tectonic plate, oceanic, and so on. This is very much a connected view of the world: nothing is isolated and totally independent; everything is part of something bigger, and everything comprises many interacting parts — subsystems."

"There seem to be two fundamental schisms in thinking: the hard/soft and the open/closed."

"Hard systems viewpoints are basically those held by designers and engineers who are trying to create systems to meet an understood need in an effective and economic manner. Those in the soft camp caricature the approach as head-down, concerned with optimization, obsessed with quantitative metrics and highly pragmatic. So much so, in fact, that the term system thinking has been purloined by the soft camp as though they alone thought! The soft camp use the term engineer’s philosophy, not too endearingly, to describe the hard approach, in which the requirement is stated by a customer and the engineer satisfies the requirement without question."

"Soft systems viewpoints are those held by behavioural, management, social anthropology, social psychology and other science students concerned with observing the living world, and in particular the human world. Human activity systems (HASs) are messy, in that they do not exhibit a clear need or purpose - if they can be said to exhibit purpose at all. Indeed, so complex is the real world of people that the idea of driving towards optimal solutions may be a non-starter - perhaps we should see if we can simply understand and concern ourselves with improving the situation."

"For continued system cohesion, the mean rate of system adaptation must equal or exceed the mean rate of change of environment."

"Emergence is the phenomenon of properties, capabilities and behaviours evident in the whole system that are not exclusively ascribable to any of its parts. Classic examples of emergence include: self awareness from the human brain; the pungent smell of ammonia emerging from two colorless, odorless gases-nitrogen and hydrogen; and so on."

"Emergence is not really mysterious, although it may be complex. Emergence is brought about by the interactions between the parts of a system. The galloping horse illusion depends upon the persistence of the human retina/brain combination, for instance. Elemental gases bond in combination by sharing outer electrons, thereby altering the appearance and behavior of the combination. In every case of emergence, the source is interaction between the parts — sometimes, as with the brain, very many parts — so that the phenomenon defies simple explanation."

"The motives for conceiving modern systems engineering are to be found, at least in part, in past disasters. Arthur D. Hall III [1989] cites: the chemical plant leakage in Bhopal (1986); the explosion of the NASA Challenger space shuttle (1986) and the Apollo fire (1967); the sinking of the Titanic (1912); the nuclear explosion in Chernobyl (1986) and the disaster at Three Mile Island power plant (1979). He cites, too, the capture of markets by Japan from the U.S., the decline in US productivity and the failure of the US secondary school system. He identifies the millions of people dying of starvation every year while other nations stockpile surplus food, medical disasters such as heart disease, while governments subsidize grains used to produce high cholesterol meat, milk and eggs; and many more. One implication is clear: systems engineering faces challenges well beyond the sphere of engineering."

"“The term (system-of-systems) is being applied to the creation of new systems by bringing together existing operational systems under a single umbrella and, presumably, creating or adapting links and interactions between the operational systems, which become subsystems of the higher level umbrella system.”"

"Architecture is defined as the art and science of creating buildings. Systems engineering may be similarly defined as the art and science of creating systems."

"Derek Hitchins has had several careers. He served as an engineer officer in the RAF for 22 years, retiring as a wing commander. He worked in industry for some 17 years, variously as systems design manager, future projects manager, technical director, marketing director and business development director for systems companies. For five years, he taught integrated science and physics (plus singing and trampoline) in a grammar school. And he was a university professor for seven years, before being obliged to retire from full time academia on health grounds. Presently: author, consultant and occasional lecturer on systems, systems thinking, chaos and systems engineering – contemporary and ancient."

"[The process of system design is]... consisting of the development of a sequence of mathematical models of systems, each one more detailed than the last."

"[The word system is often defined in a way] that seems the most appropriate for the purpose of any given discussion."

"The problem of the design of a system must be stated strictly in terms of its requirements, not in terms of a solution or a class of solutions."

"Every author has several motivations for writing, and authors of technical books always have, as one motivation, the personal need to understand; that is, they write because they want to learn, or to understand a phenomenon, or to think through a set of ideas."

"If all the theories pertinent to systems engineering could be discussed within a common framework by means of a standard set of nomenclature and definitions, many separate courses might not be required."

"Only if mathematical rigor is adhered to, can systems problems be dealt with effectively, and so it is that the systems engineer must, at least, develop an appreciation for mathematical rigor if not also considerable mathematical competence."

"All that can be done pedagogically is to show the student how some phenomena have been modeled, let him model some phenomena under supervision, and then hope he will be successful on his own—or know enough to secure assistance."

"In the minds of many writers systems engineering is synonomous with component selection and interface design; that is, the systems engineer does not design hardware but decides what types of existing hardware shall be coupled and how they shall be coupled. Complete agreement that this function is the essence of systems engineering will not be found here, for, besides the very important function of systems engineering in systems analysis, there is the role played by systems engineering in providing boundary conditions for hardware design."

"Over 80 million people have participated in Cub Scout Pinewood Derbies. Pinewood is a case study of the design of a Cub Scout Pinewood Derby for one particular scout pack. The system helps manage the entire race from initial entry through final results. Many alternatives for race format, scoring, and judging are presented."

"After earning the PhD degree and acquiring some relatively extensive experience in digital computers… It was time to leave the University. The result of an extensive search for the right job was a family move to Arlington Heights, Illinois, where it was a short commute to the Research Laboratories of the Pure Oil Company at Crystal Lake. I was given the title of Mathematical and Computer Consultant. The Labs were set in a beautiful campus, the professional personnel were eager to learn what I had to teach and to include me in many interesting projects where my knowledge and skills could be put to good use. I was encouraged to initiate my own program of research. I went to work with enthusiasm. The corporate headquarters of Pure Oil were located in down town Chicago. Pure Oil had been trying to install an IBM 705 computer system for all their accounting needs including calculation of all data necessary for the management of exploration, drilling, refining and distribution of oil products and even royalties to shareholders in oil wells. Typical for those early days, the programming team was in deep difficulties and needed help; they lacked adequate resources and suitable training. The Executive Vice President of Pure Oil, when he heard that there was a computer expert already on the payroll at the Crystal Lake lab, ended our family blissful dream and I was reassigned to the down town office."

"During this period I was able to carry out only one project of real interest to me. Pure Oil was a fully integrated oil company in the sense that they engaged in exploration for oil, construction of oil wells, production of crude oil, transportation to refineries, distribution of refinery products to company owned storage facilities and to gas stations. We developed a linear programming model of the whole network hoping to discover the optimum allocation to and from connected nodes in order to meet required deliveries at minimum cost. Then we collected all the data needed by our model and ran the model. The computations took several days and the results were disappointing: The optimum allocations were not significantly different from their current practices. Is it possible that we had discovered a system of human beings in which everyone knew the payoff functions and constraints, and, over time, had evolved behavior patterns that enabled them to achieve near optimum performance? Or was it possible that our model was not detailed enough as it was based so closely on current practice that no new behavior could emerge? Or was our data incorrect? This was disappointing but great experience."

"[In the year 1957] I have just returned from an exciting meeting of the American Society for Engineering Education where I heard a paper on the new discipline of systems engineering. It is no longer sufficient for engineers merely to design boxes such as computers with the expectation that they would become components of larger, more complex systems. That is wasteful because frequently the box component is a bad fit in the system and has to be redesigned or worse, can lead to system failure. We must learn how to design large-scale, complex systems from the top down so that the specification for each component is derivable from the requirements for the overall system. We must also take a much larger view of systems. We must design the man-machine interfaces and even the system-society interfaces. Systems engineers must be trained for the design of large-scale, complex, man-machine-social systems."

"In the folklore of systems engineering, there are sayings, “If it isn't testable, it isn't a requirement,” and, “If it is not quantifiable, it is not testable.” I had always tended to subscribe to the particle of wisdom in these sayings. One of the many lessons that I learned from the CATIE experience, however, was that systems engineering had to be able to deal directly and purposively with what are usually considered to be strictly qualitative (unquantifiable) aspect of systems, such as quality of life, for example. The agricultural practices of these small farmers in Central America is such a large part of their lives that to change any part of their agricultural practices might be seen as diminishing their quality of life - even with respect to the color of the beans that the new practices might require. But even if we cannot deal directly with quality of life or user friendliness or enmity/sympathy, we can identify quantifiable figures of merit relating to these qualitative aspects and if we find enough figures of merit and combine them suitably, we might eventually obtain agreement that we have captured the essence of the qualitative aspect, at least as far as this particular set of stakeholders is concerned."

"General systems theory is considered as a formal theory (Mesarovic, Wymore), a methodology (Ashby, Klir), a way of thinking (Bertalanffy, Churchman), a way of looking at the world (Weinberg), a search for an optimal simplification (Ashby, Weinberg), didactic method (Boulding, Klir, Weinberg), metalanguage (Logren), and profession (Klir)."

"Wayne Wymore is now well established as an important leader in systems engineering and a founder of a highly original "school of thought" in the area of systems design. His contribution to this area, which will be the subject of a special issue of this journal in the near future, is best exposed in a trilogy consisting of this book and its two predecessors [Wymore, 1967, 1976]. Wymore's approach to systems design is characterized by mathematical rigor, comprehensiveness, and broad applicability."

"A. Wayne Wymore founded the first academic department of Systems Engineering in the world at the University of Arizona in 1960. He pioneered Mathematical-based Systems Engineering and later led Model-based Systems Engineering. He was an early and ardent supporter of the fomenting of INCOSE. He has led self-evaluation of Systems Engineering education, and continues to be one of the most prominent theoreticians of the Systems Engineering community. In addition to his teaching, writing, and consulting, he has participated in pro bono projects to bring a Systems Engineering approach to social service organizations."

"System design can be requirements based, function based, or model based. Model based system engineering and design has an advantage of executable models that improve efficiency and rigor. One of the earliest developments of this technique was Wymore’s (1993) book entitled Model-based System Engineering, although the phrase “model-based system design” was in the title and topics of Rosenblit’s (1985) PhD dissertation. Model-based systems engineering depends on having and using well-structured models that are appropriate for the given problem domain."

"Wayne’s book, A Mathematical Theory of Systems Engineering: The Elements, John Wiley, New York [1967] appeared in an era that spawned the concept of a mathematical system as a generalization of the control systems of engineers and the automata theories of computer scientists. Wymore employed the unusual term “Tricotyledon Theory of System Design” to portray the tri-partite nature of his theory. Tricotyledon, or three leaved seed, pictures a leaf for the class of models of the behavior of the system being designed, a second leaf for the technologies that are available to implement the system, and a leaf for the intersection of the two previous classes, namely, the technologies that can implement the models according to specified evaluation criteria. In subsequent work over three decades, he deepened the theory and applied it to numerous system engineering problems. The theory became the basis for his book, Model-based System Engineering, CRC Press, Inc. Boca Raton, FL, USA © 1993 and helped to spawn the trend toward use of systems modeling tools for systems design. However, Wayne himself did not emphasize the use of modeling and simulation as essential tools in systems engineering practice."

"An enterprise architecture can be thought of as a "blueprint" or "picture" which assists in the design of an enterprise. The enterprise architecture must define three things. First, what are the activities that an enterprise performs? Second, how should these activities be performed? And finally, how should the enterprise be constructed? Consequently, the architecture being developed will identify the essential processes performed by a virtual company, how the virtual company and the agile enterprises involved in the virtual company will perform these processes, and include a methodology for the rapid reconfiguration of the virtual enterprise."

"The presence of an enterprise reference architecture aids an enterprise in its ability to understand its structure and processes. Similar to a computer architecture, the enterprise architecture is comprised of several views. The enterprise architecture should provide activity, organizational, business rule (information), resource, and process views of an organization."

"Enterprise Engineering is defined as that body of knowledge, principles, and practices having to do with the analysis, design, implementation and operation of an enterprise. In a continually changing and unpredictable competitive environment, the Enterprise Engineer addresses a fundamental question: “how to design and improve all elements associated with the total enterprise through the use of engineering and analysis methods and tools to more effectively achieve its goals and objectives”..."

"A discipline has six basic characteristics:"

"Reference disciplines are existing bodies of knowledge that help establish the new discipline, that are a foundation of support for future work, and that are logical linkages to previous works. Throughout history, new disciplines have emerged from the need to solve new problems that are not fully addressed by existing disciplines. Emerging disciplines build upon the knowledge, subject matter, methods, tools, and theories of existing reference disciplines."

"There are several world view assumptions present in enterprise engineering. The first assumption is that the enterprise can be viewed as a complex system. This is necessary because systems in organizations are systems of organized complexity. Complexity is the result of the multiplicity and intricacy of man’s interaction with other components of the system. Secondly, the enterprise is to be viewed as a system of processes. These processes are engineered both individually and holistically. The final assumption is the use of engineering rigor in transforming the enterprise. The enterprise engineering paradigm views the enterprise as a complex system of processes that can be engineered to accomplish specific organizational objectives. In the Enterprise Engineering paradigm, the enterprise is viewed as a complex system of processes that can be engineered to accomplish specific organizational objectives."

"An enterprise must be viewed from several perspectives if it is to be fully described and understood (Barnett 1994; ESPIRIT Consortium AMICE 1991). Previous work in the development of architectures by the Automation & Robotics Research Institute (Presley et al. 1993) describes a five view approach. The Business Rule (or Information) View defines the entities managed by the enterprise and the rules governing their relationships and interactions. The Activity View defines the functions performed by the enterprise (what is done) while the Business Process View defines a time sequenced set of processes (how it is done). The resources and capabilities managed by the enterprise are defined in a Resource View. Finally, the Organization View is used to define how the enterprise organizes itself and the set of constraints and rules governing how it manages itself and its processes."

"There is a paradigm shift towards a distributed and integrated enterprise. Currently, computer systems that support enterprise functions were created independently. This hampers Therefore, there is a need for a computer based data model which provides a shared and well defined terminology of an enterprise, and has the capability to deductively answer common sense questions. This paper discusses how TOVE tackles these needs by defining a framework for modeling generic level representations such as activities, time, and resources. Since there has never been a well-defined set of criteria to evaluate such models, this paper also introduces a set of evaluation criteria which may be used to evaluate modelling efforts."

"Various perspectives exist in an enterprise, such as efficiency, quality, and cost. Any system for enterprise engineering must be capable of representing and managing these different perspectives in a well-defined way."

"As information systems play a more active role in the management and operations of an enterprise, the demands on these systems have also increased. Departing from their traditional role as simple repositories of data, information systems must now provide more sophisticated support to manual and automated decision making; they must not only answer queries with what is explicitly represented in their Enterprise Model, but must be able to answer queries with what is implied by the model. The goal of the TOVE Enterprise Modelling project is to create the next generation Enterprise Model, a Common Sense Enterprise Model. By common sense we mean that an Enterprise Model has the ability to deduce answers to queries that require relatively shallow knowledge of the domain."

"In , we want to define the actions performed within an enterprise, and define constraints for plans and schedules which are constructed to satisfy the goals of the enterprise. This leads to the following set of informal competency questions:"

"We consider an organization to be a set of constraints on the activities performed by agents. This view follows that of Weber, who views the process of bureaucratization as a shift from management based on self-interest and personalities to one based on rules and procedures. Mintzberg [1983] provides an early (and informal) analysis of organization structure distinguishing among five basic parts of an organization and five distinct organization configurations that are encountered in practice. This “ontology” includes several mechanisms that together achieve coordination, like goals, work processes, authority, positions and communication. The various parts of an organization are distinguished by the specific roles they play in achieving coordination with the above means. The “” (Winograd 1987) on cooperative work in organizations provides an ontology that emphasizes the social activity by which “agents” generate the space of cooperative actions in which they work, rather than the mental state of individuals. The basic idea is that social activity is carried out by language and communication."

"Pestel was a very forceful person and quickly saw the power of system dynamics."

"No plea about inadequacy of our understanding of the decision-making processes can excuse us from estimating decision making criteria. To omit a decision point is to deny its presence – a mistake of far greater magnitude than any errors in our best estimate of the process."

"[The engineer] must identify the significant and critical problems, but in his education, problems have been predetermined and assigned. He must develop the judgment to know what solutions to problems are possible, but in school the problems encountered are known to have answers. He should be excited by new and unsolved challenges, but for 20 years he has lived in an educational system where he knows he is repeating the work of last year's students."

"The enterprise engineer must be a leader, a designer, and a synthesizer. He is a doer. He understands theory as a guide to practice. He must concern himself with human organization because the pace and success of technology are becoming more dependent on interaction with the social system and less on scientific discovery. In private as well as public research and development, such men must find ways to reverse the deterioration of ethics and efficiency. They will strengthen the information links between physical design and the public so that technology can better serve society. In the public sector they must show the level of wisdom and leadership that can co-ordinate great engineering projects with politics. They will recognise that informing the public and becoming a nucleus for crystallising public opinion is even more important in many programmes than is the underlying science."

"In concept a feedback system is a closed system. Its dynamic behavior arises within its internal structure. Any action which is essential to the behavior of the mode being investigated must be included inside the system boundary."

"Formulating a model of a system should start from the question “Where is the boundary, that encompasses the smallest number of components, within which the dynamic behavior under study is generated?”"

"In complex systems cause and effect are often not closely related in either time or space. The structure of a complex system is not a simple feedback loop where one system state dominates the behavior. The complex system has a multiplicity of interacting feedback loops. Its internal rates of flow are controlled by nonlinear relationships. The complex system is of high order, meaning that there are many system states (or levels). It usually contains positive-feedback loops describing growth processes as well as negative, goal-seeking loops. In the complex system the cause of a difficulty may lie far back in time from the symptoms, or in a completely different and remote part of the system. In fact, causes are usually found, not in prior events, but in the structure and policies of the system."

"The strongest criticism has come from some economists. The objections range from simple misunderstanding, through belief that essential structures have been omitted from the world model, to concern over the costs and feasibility of halting economic growth. Although there is a basis for the criticisms, they have not had sufficient substance to dismiss the central issues. The debate seems to be gradually moving away from the question of whether or not industrial growth must slow to the question of what strategy should be used to limit growth. The latter question, however, remains unanswered."

"In spite of the tentative nature of the world model described here, various conclusions are drawn from it. Man acts at all times on the models he has available. Mental images are models. We are now using those mental models as a basis for action. Anyone who proposes a policy, law, or course of action is doing so on the basis of the model in which he, at that time, has the greatest confidence. Having defined with care the model contained herein, and having examined its dynamic behavior and implications, I have greater confidence in this world system model than in others that I now have available. Therefore, this is the model I should use for recommending actions. Those others who find this model more persuasive than the one they are now using presumably will wish to employ it until a better model becomes available."

"It is to be hoped that those who believe they already have some different model that is more valid will present it in the same explicit detail, so that its assumptions and consequences can be examined and compared. To reject this model because of its shortcomings without offering concrete and tangible alternatives would be equivalent to asking that time be stopped. But the world will continue to turn. We always use the most acceptable model at any point in time. But how should we proceed so that the most acceptable model is also the best one that is available? We should try for three things. First, the best existing model should be identified at each point in time. Second, the best currently existing model should be used in preference to traditional models that may be less clear and less correct. Third, aggressive effort should be devoted to a continual improvement in the available models of the world system."

"It seems traditional for explicit models of social systems to be greeted by vague criticisms about their lack of perfection. Instead, we need equally explicit alternatives with a demonstration that the alternative leads to a different and more plausible set of conclusions. By proposal and counter proposition our understanding of social systems can advance."

"There may be no realistic hope of the present underdeveloped countries reaching the standard of living demonstrated by the present industrialized nations. The pollution and natural-resource load placed on the world environmental system by each person in an advanced country is probably 20 to 50 times greater than the load now generated by a person in an underdeveloped country. With 4 times as many people in the underdeveloped countries as in the present developed countries, their rising to the economic level that has been set as a standard by the industrialized nations could mean an increase of 10 times in the natural-resource and pollution load on the world environment. Noting the destruction that has already occurred on land, in the air, and especially in the oceans, capability appears not to exist for handling such a rise in standard of living. In fact, the present disparity between the developed and underdeveloped nations may be equalized as much by a decline in the developed countries as by an improvement in the underdeveloped countries."

"Professor Forrester told the National Academy of Engineering this fall, the "enterprise engineer," cast in the mold of the "professional engineer of folklore," is needed now more than ever before "to resynthesize the fragments caused by the specialization of other man"."

"Mesarovic and Pestel are critical of the Forrester-Meadows world view, which is that of a homogeneous system with a fully predetermined evolution in time once the initial conditions are specified."

"Another tradition in systems theory, known as system dynamics, originated at Massachusetts Institute of Technology. The founder of this tradition was Jay Forrester, a creative engineer who invented the magnetic core memory for computers and who built the , which is now in the Smithsonian Institution."

"We are in rapid transition today to a new world which threatens to be dominated by technological advance. In that new World. (1) man will have learned so much about nature's store of energy and its release that he will have the ability to virtually destroy civilization; (2) production, communication and transportation will all be "automatic" --these operations of man's material world will have become so vast and complex that they will have to proceed with a minimum of participation by man, his muscles, brains and senses; and (3) man will conquer space."

"Well, Benny, now that we know the thing can fly, all we have to do is improve its range a bit."

"In April 1946, when I came to Hughes Aircraft to institute high-technology research and development, it was far from the place it was to become. Howard Hughes, I was informed, rarely came around. When he did show up, it was to take up one or another trivial issue. He would toss off detailed directions, for instance, on what to do next about a few old airplanes decaying out in the yard or what kind of seat covers to buy for the company-owned Chevrolets, or he would say he wanted some pictures of clouds taken from an airplane. An accountant from Hughes Tool Co. ((started by Howard's father)) had the title of general manager but was there only to sign checks. A few of Howard's flying buddies were on the payroll, using assorted fanciful titles like some in Gilbert and Sullivan's Mikado, but apparently did next to nothing. A lawyer was on hand to process contracts, but there were practically none. In addition to the Spruce Goose flying freighter, a mammoth eight-engine plywood seaplane that barely managed to fly even once, there was an experimental Navy reconnaissance plane under development (which, with Hughes at the controls, later crashed, almost killing him). The contracts for both planes had been canceled. Perhaps, I said to myself, this is one of those unforeseeable lucky opportunities. Why not use Hughes Aircraft as a base to create a new and needed defense electronics supplier?"

"My final word about editing. I was to appear on the cover of a business magazine, and the writer who came to interview me was intrigued with engineers, scientists, PhDs founding and running companies. It was somewhat more unusual back in those days than now, although it was not without ample precedents in the past. So the question he put to me right away starting the interview was, "Would you say, Dr. Ramo, that engineers make the best managers?" And I said, "Engineers make the best engineers." It may be that some engineers will have managerial talents, and be in the right place at the right time, just as may be true of lawyers or accountants or salesmen, or tax experts or whatever. Now, on the magazine then, here was this picture of me, and here was this quote: "Engineers make the best engineers." Well, someone, before the cover actually got out, knew that that was a mistake. Obviously that had been a misprint. So looking at the text, and seeing the question that was asked of me, he changed it to: "Engineers make the best managers." "I quote Dr. Ramo on engineers." All right."

"Whether what you manage is a business, hospital, university department, government agency or even a symphony orchestra or dancing school, we suspect you will find it advisable to try to prepare ahead for what might happen in the future."

"Obama can't announce that man-in-space is out of date because of the political consequences... Senators and congressmen from Florida, Texas and Alabama (centers of space-program jobs) would give him so much trouble he can't cancel it."

"Engineering is harder to get into as a girl. Schools will generally funnel girls towards law or medicine"

"It is important to remember that still only 16% of the engineering workforce are women but in society, women make up 51% of the population"

"The general public still doesn’t see engineers in the way it does doctors or lawyers. You see doctors and lawyers portrayed on television and in fiction, but engineering only has visibility in documentary formats, so Inwed has an important role to promote the profession.”"

"Teachers and parents don’t see engineers in society. Most people who become engineers already have a family member in the industry"

"I needed a third module to complete my degree and chose systems engineering, thinking that it was about computer systems,” she says. It was definitely not what she was expecting but in a good way and it moved her career firmly into the engineering sector. It is clear she now thrives on the opportunities engineering offers."