In the complex engineering work, for example, in the launching of Sputnik, the research of atomic bombs, hydrogen bombs, these very complex scientific and technological work, we find that we need a technical staff for the party leadership. That is to say, an engineer, or a chief engineer plus a few deputy chief engineers, has not been able to cope with the situation, has not been able to grasp the total complexity of the system design work, there must be a work in our work, called the overall design of the Department of Shaomen. This department is not a few people, not a dozen people, often hundreds of people, or even nearly a thousand people in the organization. Such an organization is responsible for the design of complex systems, which is necessary for the complex engineering of modern science and technology. For example, when a mason, who is an individual laborer, builds a simple house, he first has to get the materials, select a feasible plan, and then build it. Before he builds it, he has, of course, an image of the house he is going to build in his mind. He also has a plan of what to do first and what to do afterward in order to build the house. In the whole construction process, he is both the structural designer who conceives the house, and the construction worker who realizes the house from every part. He is both a managerial worker and a laborer. The two are one. Later in the handicraft workshop appeared in the division of labor based on collaboration, Marx said: many people in the network of a production process, or in different but interlinked production process, planned together in concerted labor, this form of labor is called collaboration. Marx also said: all direct social labor and *** with labor on a larger scale, are more or less need to command, in order to coordinate the activities of individuals, and to perform the production of the movement of the overall ----- different from the movement of the independent organs of this overall ---- produced by a variety of general functions. A single fiddler conducts himself; an orchestra requires an orchestra conductor. That is to say, in collective labor there is a division of functions, and within all engineering on a larger scale there is what is called a totality. The overall is in what? Is the complex engineering system inside the various parts of the coordination, so that the final system can achieve the required performance. The whole is to direct each specific component, how to design, so that the final connected whole can work better. In the handicraft workshop, this command is the supervisor, and later production further development, in the industrial revolution after the emergence of large-scale industrial production, this command is what we are accustomed to say the chief engineer. In the manufacture of a complex machine, if one of its local components is not well coordinated with each other, the final machine will not work and will not be advanced. So in the design process there is a person who coordinates all aspects of the work, and this is what we call the chief designer.
This is basically the situation in the last century or in the present century. After this century, the scale of scientific and technological activities has developed considerably, and the complexity of engineering and technological devices has been increasing. For example, in the 20th century 4O years, in the United States to develop the atomic bomb, to participate in the research work of the people a **** 1.5 million people. To the 60s when the Americans engaged in the moon landing flight, to participate in the manufacture of rockets, spaceships, the whole activity of how many people? There were 420,000 people. It can be imagined, to command the regulation of such a large social labor (it has been social labor, not personal activities), relying on a chief engineer or chief designer, no matter how much he has the ability, that is also impossible when. At this time it is necessary to enrich and expand the activities of the chief engineer and chief designer, and to organize a collective of dozens or hundreds of people to take up such a complex work. This is just proposed for the leadership to do the technical staff of the department, is no longer a person, but a department, is the overall design department. This is also the case in our country. In the late 1950s, when our country was engaged in cutting-edge technology for national defense, i.e., when we started to work on atomic bombs, hydrogen bombs, and picking up missiles, we also encountered this problem. We found that the complexity lies in the fact that the task we are engaged in is a huge system, a combination of several components that interact and depend on each other, combined to a defined set of functions and targets to be achieved. Of course there are times when we have to consider larger systems. For example, we develop a missile nuclear weapon, which in turn is a component of a larger system of our national defense forces. The strategic nuclear missile, itself, has a body, a warhead, an engine, and a guidance system. During testing, the working status of the missile is also transmitted down by radio signals, which is called remote measurement, or telemetry for short. Also, in the flight test, in order to observe the missile is not connected to the original design of the flight track flight, but also have a large set of measurement of the missile outer ballistic flight status of the ground measurement system, that is, the outer ballistic measurement system. Before launching, all parts of the missile should be tested with instruments in advance to see if they work properly before deciding whether to launch or not; if the missile uses liquid fuel, then the fuel should be added to the missile in time. At the time of launch, there is also a set of optical measurement equipment to observe whether the takeoff is normal. All of these things make up a very complex system. But that's not all. For strategic nuclear missiles, we also have to consider the specifications for accomplishing the mission, for example, what is the range? How high is the hit accuracy required? How powerful is a hydrogen warhead explosion? There are other strategic weapons to consider. For example, missiles launched by nuclear-powered submarines, as well as other weapons that do not belong to the strategic weapons, all of our national defense weapons system to have a general arrangement. In terms of the nuclear missile itself, it is a complex system, but in order to decide on the complex system of the nuclear missile, we have to consider a more complex system, including a larger system, that is, the composition of our entire national defense force. It would be difficult to envision such a complex problem to be solved by a single designer or a chief designer or several deputy chief designers.
As I said earlier, when the Americans were working on the atomic bomb, there were l5,000 people involved, and then when they were working on the moon landing flight, there were 420,000 people involved. Such a large-scale organization, linked to each part, each person's work should be arranged, such a complex system design work, of course, relying on a person a few people can not, so this gives rise to a new industry, called systems engineering, is specialized in the coordination of such a complex system to engage in the overall work. In addition to the development of complex engineering systems organization and management technology, there is another aspect of the development of foreign countries, that is, the management of large enterprises management technology, foreign countries called "management science". Business management as a science sprouted in the early years of the century under the Theravada system, and became a well-established science after the 1940s. In essence, it can be used as a system for complex projects, large corporations, and even national departments. The organization of this system and the operation of this system is an engineering practice, just as the construction of a water hub, a power grid, or a steel complex is an engineering technique. Therefore, it should be regarded as system engineering. Just as mechanical engineering, water conservancy engineering, civil engineering, electronic engineering and so on need to have to realize the theory of these projects, systems engineering also need to realize the theory of it, the scientific theory is the basis of systems engineering, systems engineering is the specific use of this scientific theory. This scientific theory can follow an already established term called operations research, but the content and scope of a clearer, it is the system organization and management of the practice of summed up, the scientific theory of universal significance.
The increasing scale of social work requires us to take into account the overall situation, comprehensive planning, local subordinate to the overall and other principles of the team's simple spontaneous application to the application of scientific consciousness, from the daily experience to the scientific theory reflecting the objective laws of organization and management work. The so-called scientific theory is to express the law in the form of numbers, and finally to be able to count on the electronic computer. This is the essence of operations research. The word "operation research" is taken from the famous ancient Chinese saying "planning in a tent, winning in a thousand li away". At the same time, it expresses a historical situation, that is, the development of operation research started from the need of military command work. In the second world war, some foreign mathematicians participated in this aspect of the work, found the military command inside some of the problems, can be turned into mathematical relations to deal with more accurate, operations research is developed from this, and gradually formed the theory of systems engineering. Operations research is not magical, it is only the reason we do things distilled into a universal theory. Take an example to illustrate. There is a method in operations research called the planning and coordination technique. In effect, it says that any task consists of one specific piece of work, and that there is a strict order of which piece should be done first and which piece should be done second. The things to be done, a circle a circle ground on a piece of paper, the first to do the drawing on the left, after the drawing on the right, to organize it. Then draw a line between the two circles indicating what must be done from the first event to the next, with an indication of how long it will take. For complex tasks, the number of steps or events is greater. In a well-drawn diagram, the team head to tail there are many lines of work, you can always find out the longest time required for a line, this line is called the key line, or in our customary language called the short line, because it is the most critical. Planning and coordination technology is to coordinate the idea of taking measures to make the critical line of time can be shortened a little. Because when it is shortened, the completion time of the whole task can be advanced. Planning and coordination technology helps us to identify the critical line. If we take measures to shorten the time of this critical line, another line may become critical, and then we take measures to change the situation of that line so that the time can be advanced. That's how the whole program coordination technique works. The example I gave shows that there is nothing magical about the nature of operations research; it organizes the things we do on a daily basis. So what do I mean by operations research? Operations Research is the science of things. There is a reason to do things, we do things every day, just do not systematize it, precise, into a theory expressed in mathematical language. Of course, these reasons to form a theory will have to come up with a name, these names are new terms, what linear programming theory, nonlinear programming theory, queuing theory, search theory, decision theory and so on.
The technique of plan coordination just mentioned, if there are hundreds of events, it can be too much work to work out the key lines manually, with an abacus, maybe for months. Before the plan is adjusted, time has passed, and the math would be a horse's ass, useless. So it is very important that after the emergence of operations research, and the emergence of electronic computers, all the calculation part of the work can be greatly accelerated, not months, just a few minutes. This makes the theory of operations research to systems engineering, become a practical can? Can, otherwise it is empty talk, can not be done. Therefore, it can be said that the systems engineering is born in response to the occasion, but also to the water. Because there is a complex system of problems, so the emergence of systems engineering. And to solve the system engineering, and must have theory, this theory from the Second World War, nearly 30 years, has been gradually improved. At the same time, and the emergence of electronic computers, for the practice of systems engineering, operations research applications provide practical possibilities. On the one hand, there is the theory of operations research, on the one hand, there are electronic computers as a computing tool, which makes the systems engineering can really be actual in, which makes the systems engineering flourish. Now the system engineering method has been widely used in foreign countries in engineering design, applied to the management of enterprises. In the military command, staff work, such as the mobilization of troops, weapons equipment, the use of systems engineering methods to put forward the views of the staff, which is called military systems engineering. Among the effective methods of systems engineering, there is also a method of warehouse management. Our warehouse management, there are indeed many problems, the various subordinate units in the warehouse in the end some of the things, the supervisor is often confused. Some things are shelved for more than ten years, twenty years. Good management of warehouses, but also with a scientific approach, of course, we need to have a good warehouse manager like Daqing Oilfield Qi Lili, but the more complex warehouses, to improve the efficiency of the warehouse, we need to use the inventory theory and other systems engineering methods.
Systems engineering applications are very wide, to engineering construction, called engineering systems engineering, to business management, called production systems engineering, to military command, called military systems engineering, to the management of warehouse materials, called warehouse systems engineering.
Two, artificial systems and natural systems
Natural systems, also known as the natural system, is the universe of the giant system of hundreds of millions of years in the natural formation of a variety of self-circulating systems, such as celestial bodies, the Earth, the ocean, ecological, meteorological, biological and so on. It is also a high-order complex self-balancing system, such as the innate operation of celestial bodies, the cycle of seasons, the ecological cycle of plants and animals on the earth, up to the food chain, and other various systems to maintain human life are automatically balanced at high speed. In nature, the circulation and evolution of the material flow is the most important, there is no end to the natural environmental system, no abolition, only the cycle and development from one level to another.
Artificial systems, also known as man-made systems or man-made systems, are systems that exist in the natural system through human labor artificially designed and manufactured system, which, like the natural system, has a series of system characteristics such as wholeness, purpose, relevance, complexity, randomness, and dynamics. Such as artificial satellite systems, air transport and shipping systems, mechanical equipment systems, transportation systems.
There is an interface between natural and artificial systems. The two are both distinct and interpenetrating and influencing each other. Primitive human beings have little influence on natural systems. But in recent years, with the accelerated development of science and technology, also began to have a certain impact on the natural system, which benefits mankind, but also bring harm and disaster to the human society, and therefore cause great concern. Through the development of human wisdom and high-tech industrialization, natural resources are constantly being developed and utilized in depth, which on the one hand creates a high degree of material civilization and enjoyment of life for people, but on the other hand brings about problems such as environmental pollution and destruction of ecological balance, which have directly threatened the survival and safety of human beings themselves. Therefore, the United Nations issued an appeal to the world through the Brazilian Conference, requesting all countries to pay attention to environmental protection and ecological balance, so as to ensure the sustainable and coordinated development of human society.
Systems as the object of systems engineering research, most of the system, including both artificial systems and natural systems of the composite system, such as socio-economic planning system, military combat confrontation system, etc., which involves both geography, climate and other natural environmental systems, but also involves the artificial system, that is, through the planning and confrontation of the simulation and other means of socio-economic and military systems to carry out direct intervention, with a view to achieving the desired goals. goals.
Three, general systems and general systems theory
People in their daily lives, work in the body are specific systems, such as: transportation systems, commercial systems, financial systems, industrial systems, agricultural systems, educational systems, economic systems, arts and culture systems, military systems, social systems and so on. People cannot exist apart from systems, so to speak. So what is a general system? General system means that we do not study the composition of a specific system, specific structure, specific relationships and specific operation process, but to study all systems have the **** the same, general characteristics and laws, this abstract system is called "general system". The purpose of the study of the general system is to more y understand the general laws of system evolution, so that people from the whole to better grasp the development of the system.
The biologist Bertalanffy, at the beginning of this century, in response to the prevailing mechanistic view and method of breaking down natural phenomena, pointed out that "it is not possible to study the parts and processes in isolation, but it is also necessary to study the interactions of the parts, and the organisms should be taken into consideration as a whole or a system", and thus put forward the existence of the principle of applying to the generalization of the system and the law, and so "there is a need for a theory which is not a theory belonging to the specialized system, but a theory of the general system. is not a theory belonging to specialized systems, but is a general principle applicable to generalized systems" and called it "general systems theory."" Its subject matter expresses and derives principles that are valid for general systems."
What are the general laws of general systems that are universally applicable? For example, the system has a "wholeness", that is to say, the system can not be divided into elements to study in isolation, attention should be paid to the study of the elements and the elements of the interaction and mutual influence. Starting from the holistic nature of the system, it can lead to a basic system view, that is, "the overall function of the system is greater than the function of the elements of the organization and the system", for example: people often say that "three ignorant cobblers are equal to a Zhu Geliang," and its significance lies in this. Of course, the interaction and mutual influence may also be negative, mathematically known as "negative", can also lead to "three monks have no water to eat", the reason is that their energy consumption in the internal consumption. Again, the general system has more "hierarchical", that is, from the system structure is hierarchical, such as the administrative system is divided into sections, divisions, bureaus, ministries, commissions ...; military system is divided into platoons, companies, battalions, regiments, divisions, the army ... operation, are the system to show the hierarchical nature. Also, the general system has a "dynamic", that is, any system is not static, but all the time in motion, development. General system also has other general properties, such as "isomorphism" and so on.
Four, system theory, cybernetics and information theory
The 1940s, due to the natural sciences, engineering technology, social sciences and thinking sciences of the interpenetration and intermingling of the convergence of the system theory with a high degree of abstraction and a wide range of synthesis of the theory of systems, cybernetics and information theory.
Systems theory is the study of the pattern, performance, behavior and laws of the system of a science. It provides general methodological guidance for people to understand the composition, structure, performance, behavior and developmental laws of various systems.
The founder of systems theory was the Austrian-American theoretical biologist and philosopher Ludwig Bertalanffy. A system is composed of a number of interconnected basic elements, and it is an organic whole with defined characteristics and functions. For example, the solar system consists of the Sun and its planets (Venus, Earth, Mars, Jupiter, etc.) and satellites that orbit around it. At the same time, the solar system as a "whole" is an integral part of the "greater whole" to which it belongs - the Milky Way. Specific systems in the world are complex and must be classified according to certain criteria in order to analyze, study and manage them, e.g.: education systems, health systems, astronautical systems, communication systems, etc. If the system has exchanges of matter, energy and information with the outside world or the external environment in which it is located, then the system is an open system, otherwise it is a closed system. Open system has a strong vitality, it may promote the rapid growth of economic strength, so that the backward areas as early as possible to embark on modernization. For example, since the reform and opening up has greatly enhanced our comprehensive national strength. And many of our remote mountainous rural areas, due to the inconvenience of transportation, relatively closed, is still in a relatively backward state.
One of the purposes of people's research and understanding of the system is to effectively control and manage the system. Cybernetics, on the other hand, provides general methodological guidance for people's management and control of the system, which is a comprehensive science formed by the interpenetration of mathematics, automatic control, electronics, mathematical logic, biological sciences and other disciplines and technologies.? The ideological origins of cybernetics can be traced back to remote antiquity. However, the formation of cybernetics as a relatively independent scientific discipline began in the 1920s and 1930s of this century, and in 1948 the American mathematician Wiener published the book "Cybernetics", marking the formal birth of cybernetics. Over the decades, cybernetics has developed greatly in the vertical direction and has been applied to various fields of human society, such as economic cybernetics, social cybernetics and population cybernetics.
In order to correctly recognize and effectively control the system, it is necessary to understand and master the flow and exchange of all kinds of information of the system, and information theory provides general methodological guidance for this. Language is a tool for the exchange of information between people, the written word to expand the scope of information exchange, the invention and application of the telephone and telegraph in the 19th century to make the exchange of information into the era of electrification. Information theory, which first arose in the field of communication, now constitutes one of the three pillars of modern civilization, together with materials and energy. The concept of information has penetrated into all fields of human society, so people say that it is now the information society and the information age. The U.S. government has put forward a grand plan to build an information superhighway, which has received wide support at home and abroad. Developed countries such as Europe and Japan have responded positively to this plan, and our government has also allocated huge sums of money to keep pace with the world's development in this high-tech field.
Fifth, the system environment and constraints
Systems are usually regarded as organic wholes composed of interacting elements and having specific functions. A system, in turn, is a relative concept, and the system itself is a component of another, larger system. Therefore, a particular system can not be all-encompassing, it is always necessary to draw a line between it and other systems, this line is usually called the system boundary. The set of all parts outside the boundary that are related to the system is called the system environment. The system has relative independence from the environment. Changes in the system environment has an impact on the system itself, the system action will also cause changes in certain environmental factors, so system workers to study and analyze the system, must be clear about the system's environment and boundaries, to understand the environmental elements related to the system. System environment is not only the structural performance of the system equipment or electrical performance of certain requirements, and sometimes the parameters of the environmental conditions as the system's input parameters, information and external constraints on the operation of the system.
The term constraints comes from the optimization theory in operations research, usually refers to a set of mathematical formulas or models reflecting the laws of objective things in its optimization of the scope of application and limitations, generally using simple numbers or mathematical equations. In systems engineering refers to the system model and external equipment environment for optimization of specific constraints.
Take the optimization model of linear programming most commonly used in operations research as an example, let the factory wants to produce A, B two products, known that the factory may be put into production of equipment, raw materials, the total amount and the unit consumption of the two products in Table 16-1:
Table 16-1 Production Unit Product Resource Consumption
Resources/Unit Consumption/Products
A Product
Product B
Resource Ownership
Equipment
Raw Material A
Raw Material B
1
4
0
2
0
4
8 units of time
16 kg
12 kilograms
The total number of table-hours for the equipment is 8, which is a limiting condition for production. Similarly, raw materials A, B are limited to 16 kg and 12 kg respectively. Assuming that X1, X2 are the output of products A and B. Z represents the profit, the planning problem can be expressed as a mathematical model: the objective function MaxZ = 2X1 + 3X2
Satisfy the constraints: X1 + 2X2 ≤ 8; 4X1 ≤ 16; 4X2 ≤ 12; X1, X2 ≥ 0.
The total number of equipment hours is 8, which is a condition that restricts the output. Similarly, the limits of raw materials A, B are 16 kilograms and 12 kilograms respectively. Assuming that X1, X2 are the output of product A, B. Z represents the profit, the planning problem can be expressed in a mathematical model: objective function MaxZ = 2X1 + 3X2
Satisfy the constraints: X1 + 2X2 ≤ 8; 4X1 ≤ 16; 4X2 ≤ 12; X1, X2 ≥ 0.
Sixth, the structure and function of the system
The structure and function of the system is the basic scope of systems science, any system has a certain structure. The structure of the system is to maintain the integrity of the system and has all the functions of the internal basis, but also the system is the organic connection between the constituent elements in space and time and the interaction between the way or order.
The structure of the system as a whole has the following characteristics: (1) stability. Stability is a fundamental characteristic of the existence of the system. Once the structure of a system is formed, it always tends to maintain a certain state; (2) Hierarchy. It contains hierarchy and multilaterality. The former belongs to the upper and lower levels of vertical multi-level relationship, in which the lower level of the system is an organic part of the higher level of the system structure; multi-faceted refers to the same level of complex systems can be horizontally spread a number of interlinked and mutual constraints and their independent parallel parts; (3) variability. The system is in the environment, always with the outside world for energy, material, information exchange, so it is possible to produce from the quantitative change, sequential change to the qualitative change process, which exists in the variability; (4) relativity. Mutability is absolute, stability is relative. The relationship between the system and the environment, the system and the elements are all relative. The objective world is infinite, so the structural form of the system is also infinite.
There are three types of basic structural forms that constitute a system: type 1 is a centralized system; type 2 is a decentralized system; and type 3 is a multilevel stepwise system.?
For centralized systems, the system has n subsystems that are centralized to the upper level (called the coordinator) and are directed by it so that the system operates in a satisfactorily coordinated working state. This type of system has good total coordination performance, but the system cannot be too large, otherwise the coordinator is overburdened; in addition, once the coordinator at the upper level fails, the entire system disintegrates. Decentralized system as the name suggests is a subsystem of decentralized work, at most, there are some information transfer between subsystems. This type of system operation is simple, equivalent to around *** with the purpose of "independent combat", and when one or a few subsystems appear paralyzed, the whole system is basically still running; the disadvantage is that it is difficult to run the system in the overall most ideal state. The current urban transportation management system belongs to this type of system. Multi-level recursive systems are characterized by a hierarchical structure, where each level manages only a certain range, and the recursion is the dimensionality reduction. This type of system concentrates the advantages of the last two types of systems and overcomes their shortcomings, which can achieve the overall optimization and improve the reliability of the system. Therefore, this type of system is currently a large number of existing, such as administrative management of administrative organizations and the division of the hierarchy is a multi-level recursive order structure. Enterprise computer network systems can also be installed into this type of system.
The above describes the three basic system structure. When we construct a system, it can be a variation or composite of the above basic system structures.
The function of the system is inseparable from the structure. If the structure is the order of the system's internal linking action, then the function is the order and ability of the system's external linking action. The function of the system is subject to the constraints of the external environment and the internal structure of the system, which reflects the relative independence and absolute dependence of the function on the structure of the twofold relationship.
System function embodies the material, energy, information input and output transformation relationship between the system and the external environment, the system input and output with the interaction of the external medium is the function of the system. System function is also the ability to achieve system goals.
VII.
References:
1. System
Systems concept comes from the long-term practical activities of mankind and scientific summarization." The word "system" has been used as early as in the ancient Greek era, Aristotle's views on wholeness, purpose, organization, and the idea of interconnectedness of things, is a simple concept of the ancient system. China's ancient thinker Lao Tzu used the ancient simple philosophical thought of materialism to elucidate the unity and wholeness of the natural world. since the 19th century, the natural sciences have made great achievements, which have greatly improved mankind's understanding of the interconnectedness of the natural world. The dialectical materialism of Marx and Engels holds that the material world is a unified whole formed by countless interconnected, interdependent, mutually constraining and interacting things and processes. This is the essence of the concept of system. Qian Xuesen pointed out that "system thought is a dialectical thinking tool for analysis and synthesis, which has acquired philosophical expression in dialectical materialism, quantitative expression in operations research and other system sciences, and rich practical content in system engineering." He also explains, "The achievements of modern science and technology in the middle of the 20th century, which provided quantitative methods and computational tools for systems thinking, are a broad picture of how systems thinking has evolved from empirical to philosophical to scientific, and from contemplative to qualitative to quantitative."
The word "system" comes from a Latin word meaning "group" and "collection." In Wechsler's Dictionary, the word "system" is defined as "an organized or organized whole", "a synthesis of concepts and principles that form a collective whole", and "a collection of objects united by regular interactions or interdependence". Therefore, the "system" can be defined as a certain function, have an organic connection between each other, composed of many elements of the whole.
Based on the system of thought to establish a complete scientific system called systems science. Its basic theory is systematics; its technical basis is operations research, cybernetics, information theory, etc.; its applied technology is systems engineering.
Systems science studies the concepts, properties and evolutionary laws of systems in general and complex systems in particular. It is reflected in the natural world in the various sciences, various fields of systems in the **** the same thing.? Systems engineering is the engineering technology to deal with the system, the purpose of which is to make the system to the overall optimization or satisfaction.
2. Application of systems engineering
Systems engineering is the overall starting point for the rational development, design, implementation and use of systems science engineering technology. It is based on the overall coordination of the needs of the integrated application of natural and social sciences in the relevant ideas, theories and methods, the use of electronic computers as a tool to analyze the structure of the system, the elements, information and feedback, in order to achieve optimal planning, optimal design, optimal management and optimal control of the purpose.
Systems engineering, which takes complex systems as its object of study, was first proposed and applied by the Bell Telephone Company in the 1940s, and in the 1950s, in the development of some large-scale engineering projects and military equipment systems in the U.S., it has fully demonstrated its effectiveness in solving complex and large-scale engineering problems. Subsequently, in the United States of America's missile development, Apollo moon landing program has been the rapid development of the 60's in China in the process of missile development also began to apply systems engineering technology. In the 70s and 80s, systems engineering technology began to penetrate into the social, economic, natural and other fields, and gradually decomposed into engineering systems engineering, enterprise systems engineering, economic systems engineering, regional planning systems engineering, environmental and ecological systems engineering, energy systems engineering, water resources systems engineering, agricultural systems engineering, population systems engineering, etc., and has become a well-established technical means of researching complex systems.
Systems engineering has a wide range of applications, mainly (1) engineering systems: the study of large-scale engineering project planning, design, manufacturing and operation. (2) social