系统工程第一章课件

1、Systems Engineering系统工程鄢萍 教授/博导12007 SYSTEMS ENGINEERINGSystems Engineering系统工程12007 SCourse Name: Systems EngineeringCourse Hours and Credits: 30 Hs, 2ScrsTextbook: Introduction to System Engineering Andre P. Sage George Mason UniversityIntroduction to Operation Research, Seventh Edition, Prof. Hil

2、ler, Stanford University系统工程教程：喻湘存，熊曙初，清华大学出版社系统工程，第三版，汪应洛，机械工业出版社9/25/202222007 SYSTEMS ENGINEERINGCourse Name: Systems Engineeri9/25/202232007 SYSTEMS ENGINEERING9/24/202232007 SYSTEMS ENGINEE9/25/202242007 SYSTEMS ENGINEERING9/24/202242007 SYSTEMS ENGINEETesting:Normal Testing, but the answer sho

3、uld be written in English.9/25/202252007 SYSTEMS ENGINEERINGTesting:9/24/202252007 SYSTEMSChapter 1 Introduction to Systems Engineering 62007 SYSTEMS ENGINEERINGChapter 1 Introduction to SystIntroduction to Systems Engineering1.1 THE SYSTEMS POINT OF VIEW1.2 DEFINITIONS OF SYSTEMS ENGINEERING 1.3 HI

4、STORY OF TECHNOLOGICAL DEVELOPMENT 1.4 SYSTEMS ENGINEERING KNOWLEDGE 1.5 The APPLICATION OF SYSTEMS ENGINEERING 9/25/202272007 SYSTEMS ENGINEERINGIntroduction to Systems Engine1.1 THE SYSTEMS POINT OF VIEW Because systems engineering is often described as a new way of thinking, we need to describe w

5、hat we mean by the systems point of view. This will lead us to see that it is not really new. The systems perspective takes a big picture or holistic, or gestalt, view of large-scale problems and their proposed technological solutions. 9/25/202282007 SYSTEMS ENGINEERING1.1 THE SYSTEMS POINT OF VIEW

6、1.1 THE SYSTEMS POINT OF VIEW This means that systems engineers not only examine the specifics(细节) of the problem under consideration but also investigate relevant factors in the surrounding environment. They realize that problems are embedded in a situation or environment that can have significant

7、impacts on the problem and its proposed alternative solutions. This is not to say that systems engineers do not get very detailed or specific far from it. There is also much effort devoted to in scoping, high-fidelity modeling, and specification of system requirements and architecture. 9/25/20229200

8、7 SYSTEMS ENGINEERING1.1 THE SYSTEMS POINT OF VIEW 1.1 THE SYSTEMS POINT OF VIEW The systems viewpoint stresses（讲述了） that there usually is not a single correct answer or solution to a large-scale problem or design issue. Instead, there are many different alternatives （可选方案） that can be developed and

9、 implemented depending on the objectives （目标） the system is to serve and the values of the people and organizations with a stake in the solution. Lets add more detail to what we mean by the systems point of view. 9/25/2022102007 SYSTEMS ENGINEERING1.1 THE SYSTEMS POINT OF VIEW 1.1 THE SYSTEMS POINT

10、OF VIEW First, a system is defined as a group of components that work together for a specified purpose. This is a very simple but correct definition. Purposeful action is a basic characteristic of a system. A number of functions must be implemented in order to achieve these purposes. This means that

11、 systems have functions. They are designed to do specific tasks. 9/25/2022112007 SYSTEMS ENGINEERING1.1 THE SYSTEMS POINT OF VIEW 1.1 THE SYSTEMS POINT OF VIEW Systems are often classified（分类） by their ultimate purpose: service-oriented systems, product-oriented systems, or process-oriented systems.

12、 An airport can be viewed as an example of a service system. The planes, pilots, mechanics, ticket agents, runways, and concourses are all components that work together to provide transport service to passengers and freight. An automobile assembly plant is an example of a product-oriented system. Th

13、e raw materials, people, and machines all work together to produce a finished car. A refinery that changes crude oil into gasoline is an example of a process-oriented system. 9/25/2022122007 SYSTEMS ENGINEERING1.1 THE SYSTEMS POINT OF VIEW 1.1 THE SYSTEMS POINT OF VIEW We note here that the systems

14、considered by systems engineers may be service systems, or they may be product systems. The systems may be systems designed for use by an individual or by groups of individuals. These systems may be private sector systems, or they may be government or public sector systems.9/25/2022132007 SYSTEMS EN

15、GINEERING1.1 THE SYSTEMS POINT OF VIEW 1.1 THE SYSTEMS POINT OF VIEW For Example, An overhead projector（高射投影仪） may be viewed as a system. So may the combination of an overhead projector, a screen on which it projects, and a set of overheads. The instructor using the overhead may also be included in

16、the notion of system. From another perspective, the combination of the overhead, screen, overheads, instructor, and students may be regarded as a system.“ Thus, when we use a term such as engineer a system, we must be very careful to define the nature of the system that we wish to engineer and what

17、is included in. and exempted from, the notion of system. We must also be very concerned with the interfaces to the system that we are engineering.9/25/2022142007 SYSTEMS ENGINEERING1.1 THE SYSTEMS POINT OF VIEW 1.1 THE SYSTEMS POINT OF VIEW The systems point of view also recognizes that a problem an

18、d its solution have many elements or components, and there are many different relations among them. The important aspects of a problem are often a function of how the components interact. Simple aggregation of individual aspects of a problem is intuitively appealing but often wrong. The whole is oft

19、en not simply the sum of its parts. Often, much more is involved. This does not suggest at all that scientific analysis, in which an issue is disaggregated into a number of component issues and understanding sought of the individual issues, is in any way improper. 9/25/2022152007 SYSTEMS ENGINEERING

20、1.1 THE SYSTEMS POINT OF VIEW 1.1 THE SYSTEMS POINT OF VIEWThe following steps are essential in finding solutions to large and complicated problems:Desegregation or decomposition（分解） of a large issue into smaller, more easily understandable partsAnalysis of the resulting large number of individual i

21、ssuesAggregation of the results to attempt to find a solution to the major issueThis is the essence of the formal scientific method. 9/25/2022162007 SYSTEMS ENGINEERING1.1 THE SYSTEMS POINT OF VIEWT1.1 THE SYSTEMS POINT OF VIEW However, interpretation must follow analysis, and meaningful issue formu

22、lation must precede it. Also, these formal efforts need to be conducted across a variety of life-cycle phases. The systems approach attempts to incorporate all of these. 9/25/2022172007 SYSTEMS ENGINEERING1.1 THE SYSTEMS POINT OF VIEW 1.1 THE SYSTEMS POINT OF VIEW System components are often of very

23、 different types; and it is helpful, from a systems perspective, to distinguish among them. Consider a university as a system for producing educated graduates. Some of the parts of the university system are structural or static components, such as university buildings. As the system is operating, th

24、ese structural components usually do not change much. Operating components are dynamic and perform processing such as the professors in a university who teach students. Flow components are often material, energy, or information; but in this example, students are the parts that flow or matriculate th

25、rough the university system. 9/25/2022182007 SYSTEMS ENGINEERING1.1 THE SYSTEMS POINT OF VIEW 1.1 THE SYSTEMS POINT OF VIEW Again, how the components interact is an important aspect of any system, its problems or design issues, and their alternative solutions. For example, grades are one mechanism（机

26、制） for interaction between professors and students. Grades serve a purpose, intended or not. it is important to understand what purpose, intended and unintended, they serve.9/25/2022192007 SYSTEMS ENGINEERING1.1 THE SYSTEMS POINT OF VIEW 1.1.1Attributes Characterizing Systems Four Basic Attributes o

27、f the System From among many characteristics, four basic attributes which play basic roles to characterize the system are described in the following (Hitomi, 1971): (1) Assemblage（集合、装配）. A system consists of a plural number of distinguishable units (elements, components, factors, subsystems（子系统）, e

28、tc.), which may be physical or conceptual, natural or artificial.9/25/2022202007 SYSTEMS ENGINEERING1.1.1Attributes Characterizing(2) Relationship. Several units assembled together are merely a group or a set. For such a group to be admissible as a system, a relationship or an interaction must exist

29、 among the units.1.1.1Four Basic Attributes of the System9/25/2022212007 SYSTEMS ENGINEERING(2) Relationship. Several unitEXAMPLE 1.1Logical relationship is determined essentially by definitions and assumptions, such as the relation of production, inventory, and sales in a period: Final inventory（最后

30、清单） = initial inventory + production quantity（生产数量） - sales quantity. EXAMPLE 1.2Institutional relationship（体制关系） is specified（规定，指定） by social institution, laws, and regulations, such as： tax amount （税额）= profit (or income) tax rate. 1.1.1Four Basic Attributes of the System9/25/2022222007 SYSTEMS E

31、NGINEERINGEXAMPLE 1.11.1.1Four Basic Att1.1.1Four Basic Attributes of the System(3) Goal-seeking. An actual system as a whole performs a certain function or aims at single or multiple objectives. Wherever these objectives are attained at their maximum/minimum levels, system optimization is said to h

32、ave been performed. For this purpose it is necessary to be able to measure, objectively or subjectively, the degree of attainment of the objectives. An objective that is measurable by any means is called a goal/target. 9/25/2022232007 SYSTEMS ENGINEERING1.1.1Four Basic Attributes of EXAMPLE 1.3 A ma

33、nufacturing system effectively converts resources of production into produced goods (products), attaining an objective that creates high utilities by adding values to the raw materials, resulting in superior quality, cost and delivery. 9/25/2022242007 SYSTEMS ENGINEERINGEXAMPLE 1.3 A manufacturing s

34、EXAMPLE 1.4A business management system coordinates functional divisions-production, sales personnel and finance, which constitutes the system-and allocates limited resources available to those divisions. This system aims at organizational objectives such as profit maximization, reasonable rate of r

35、eturn on capital, increase in market share, stable growth, public services (philanthropy), etc. 9/25/2022252007 SYSTEMS ENGINEERINGEXAMPLE 1.49/24/2022252007 SYS1.1.1Four Basic Attributes of the System(4) Adaptability to environment. A specific, factual system behaves so as to adapt to the change in

36、 its surroundings, or external environment. This external environment influences and is influenced by the system, in that matter and/or energy and/or information are received from and given to each other. A system that is capable of controlling itself in such a way as to be always optimal even under

37、 changes in the external environment, is called an adaptive (or cybernetic) system. 9/25/2022262007 SYSTEMS ENGINEERING1.1.1Four Basic Attributes of If this system possesses dynamic adaptability, approaching a desired state with the least time lag by changing its internal structure and functions as

38、the environment changes, it is as self-organizing system. 9/25/2022272007 SYSTEMS ENGINEERING If this system possessEXAMPLE 1.5 Human is a complete adaptive system. EXAMPLE 1.6 A business system is a self-organizing system, in that it generates a diversified variety of activities, resulting in econo

39、mies of scope. 9/25/2022282007 SYSTEMS ENGINEERINGEXAMPLE 1.59/24/2022282007 SYSA business system is an adaptive system, in that it makes proper decisions so as to achieve its objectives under severe environmental situations (competitors, markets, industrial societies, economic and political conditi

40、ons, international trends, etc.). The system often reacts to its environment to make its future behavior more effective: e.g. it performs marketing activities, such as advertising and merchandising, to enhance potential demands in the market.9/25/2022292007 SYSTEMS ENGINEERINGA business system is an

41、 adap1.1.2 Systems Defined Four Definitions of Systems On the basis of the foregoing considerations, the four essential definitions of systems can now be given as follows (Hitomi, 1975).9/25/2022302007 SYSTEMS ENGINEERING1.1.2 Systems Defined Four D1.1.2 Systems Defined (1) Abstract (or basic) defin

42、ition. On the basis of the first two attributes above, a system is a collection of recognizable units having relationships among the units. Under this definition, general system theory has been developed, wherein things are deliberated theoretically, logically, and speculatively. 9/25/2022312007 SYS

43、TEMS ENGINEERING1.1.2 Systems Defined (1) Abs1.1.2 Systems Defined(2) Structural (or static) definition. On the basis of all four attributes, a system is a collection of recognizable units having relationships among the units, aiming at specified single or multiple objectives subject to its external

44、 environment. 9/25/2022322007 SYSTEMS ENGINEERING1.1.2 Systems Defined(2) Struc1.1.2 Systems Defined(3) Transformational (or functional) definition. From the last attribute, the effects of the environment upon the system are inputs (including unforeseen disturbances), and, conversely, the effects in

45、 which the system influences the environment are outputs. From this consideration ，a system receives inputs from its environment, transforms them to outputs, and releases the outputs to the environment, whilst seeking to maximize the productivity of the transformation. 9/25/2022332007 SYSTEMS ENGINE

46、ERING1.1.2 Systems Defined(3) Trans1.1.2 Systems Defined(4) Procedural (or dynamic) definition. The process of transformation in the input-output system consists of a number of related stages, at each of which a specified operation is carried out. By performing a complete set of operations according

47、 to the precedence relationship on the stages, a function or task is accomplished. Thus, a system is a procedure-a series of chronological, logical steps by which all repetitive tasks are performed. 9/25/2022342007 SYSTEMS ENGINEERING1.1.2 Systems Defined(4) Proce1.1.3 System Life Cycles A very impo

48、rtant fundamental concept of systems engineering is that all systems are associated with life cycles. Similar to natural systems that exhibit a birth-growth-aging and death life cycle, human-made systems also have a life cycle. Most generally, this life cycle consists of definition of the requiremen

49、ts for a system, development of the system itself, and deployment of the system in an operating environment. These three essential life-cycle phases are always needed. Each of them may be described in terms of a larger number of more fine-grained phases. In all types of system evolution, and as we w

50、ill discuss, there will be a minimum of three phases:DefinitionDevelopmentDeployment9/25/2022352007 SYSTEMS ENGINEERING1.1.3 System Life Cycles A 1.1.3 System Life Cycles These comprise the essential systems engineering process activities. This life-cycle perspective should also be associated with a

51、 long-term view toward planning for system evolution, research to bring about any new and emerging technologies needed for this evolution, and a number of activities associated with actual system evolution, or acquisition. 9/25/2022362007 SYSTEMS ENGINEERING1.1.3 System Life Cycles 1.1.3 System Life

52、 Cycles Thus, we see that the efforts involved in the life-cycle phases for definition, development, and deployment need to be implemented across three life cycles that comprise:Systems planning and marketing,Research, development, test, and evaluation (RDT&E)Systems acquisition or procurement9/25/2

53、022372007 SYSTEMS ENGINEERING1.1.3 System Life Cycles Introduction to Systems Engineering1.1 THE SYSTEMS POINT OF VIEW1.2 DEFINITIONS OF SYSTEMS ENGINEERING 1.3 HISTORY OF TECHNOLOGICAL DEVELOPMENT 1.4 SYSTEMS ENGINEERING KNOWLEDGE 1.5 The APPLICATION OF SYSTEMS ENGINEERING 9/25/2022382007 SYSTEMS E

54、NGINEERINGIntroduction to Systems Engine1.2 DEFINITIONS OF SYSTEMS ENGINEERING The U.S. Department of Defense do provide generally appropriate definitions. These two definitions attempt to combine structural, functional, and purposeful views of systems engineering. It is generally accepted that we m

55、ay define things according to structure, function, or purpose. Our continued discussion of systems engineering will be assisted by the provision of a structural, purposeful, and functional definition of systems engineering. Table 1.1 presents these three definitions.9/25/2022392007 SYSTEMS ENGINEERI

56、NG1.2 DEFINITIONS OF SYSTEMS ENG1.2 DEFINITIONS OF SYSTEMS ENGINEERING TABLE 1.1 Definitions of Systems EngineeringStructureSystems engineering is management technology to assist clients through the formulation, analysis, and interpretation of the impacts of proposed policies, controls, or complete

57、systems upon the need perspectives, institutional perspectives, and value perspectives of stakeholders to issues under consideration.FunctionSystems engineering is an appropriate combination of the methods and tools of systems engineering, made possible through use of a suitable methodology and syst

58、ems management procedures, in a useful process-oriented setting that is appropriate for the resolution of real-world problems, often of large scale and scope.PurposeThe purpose of systems engineering is information and knowledge organization that will assist clients who desire to define, develop, an

59、d deploy total systems to achieve a high standard of overall quality, integrity, and integration as related to performance, trustworthiness, reliability, availability, and maintainability of the resulting system.9/25/2022402007 SYSTEMS ENGINEERING1.2 DEFINITIONS OF SYSTEMS ENG1.2 DEFINITIONS OF SYST

60、EMS ENGINEERING In our three level hierarchy of systems engineering there is generally a non-mutually exclusive correspondence between function and tools, structure and methodology, and purpose and management. A system engineering process results from efforts at the level of systems management to id