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1、Systems Engineering,系统工程鄢萍 教授/博导,2023/6/23,2007 SYSTEMS ENGINEERING,2,Course 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.Hiller,Stanford University系
2、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,2023/6/23,2007 SYSTEMS ENGINEERING,3,2023/6/23,2007 SYSTEMS ENGINEERING,4,2023/6/23,2007 SYSTEMS ENGINEERING,5,Testing:Normal Testing,but the answer should be written in English.,Chapter 1 Introduction to Systems Engineering,2023/6/23,2007 SYSTEMS ENGINEERIN
3、G,7,Introduction to Systems Engineering,1.1 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,2023/6/23,2007 SYSTEMS ENGINEERING,8,1.1 THE SYSTEMS POINT OF VIEW,Because
4、 systems engineering is often described as a new way of thinking,we need to describe what 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 technol
5、ogical solutions.,2023/6/23,2007 SYSTEMS ENGINEERING,9,1.1 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
6、a situation or environment that can have significant 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 sy
7、stem requirements and architecture.,2023/6/23,2007 SYSTEMS ENGINEERING,10,1.1 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 ca
8、n be developed and 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.,2023/6/23,2007 SYSTEMS ENGINEERING,11,1.1 THE SYSTEMS POINT OF VIEW,Firs
9、t,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 systems have fun
10、ctions.They are designed to do specific tasks.,2023/6/23,2007 SYSTEMS ENGINEERING,12,1.1 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.An airport can be viewed as an example of a servi
11、ce 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.The raw materials,people,and machines all work together to p
12、roduce a finished car.A refinery that changes crude oil into gasoline is an example of a process-oriented system.,2023/6/23,2007 SYSTEMS ENGINEERING,13,1.1 THE SYSTEMS POINT OF VIEW,We note here that the systems considered by systems engineers may be service systems,or they may be product systems.Th
13、e 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.,2023/6/23,2007 SYSTEMS ENGINEERING,14,1.1 THE SYSTEMS POINT OF VIEW,For Example,An overhead projector（高射投影仪）may be vi
14、ewed 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 the notion of system.From another perspective,the combination of the overhead,screen,overheads,instructor,and students may b
15、e 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 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 en
16、gineering.,2023/6/23,2007 SYSTEMS ENGINEERING,15,1.1 THE SYSTEMS POINT OF VIEW,The systems point of view also recognizes that a problem and 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 t
17、he components interact.Simple aggregation of individual aspects of a problem is intuitively appealing but often wrong.The whole is often 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
18、of component issues and understanding sought of the individual issues,is in any way improper.,2023/6/23,2007 SYSTEMS ENGINEERING,16,1.1 THE SYSTEMS POINT OF VIEW,The following steps are essential in finding solutions to large and complicated problems:Desegregation or decomposition（分解）of a large issu
19、e into smaller,more easily understandable partsAnalysis of the resulting large number of individual issuesAggregation of the results to attempt to find a solution to the major issueThis is the essence of the formal scientific method.,2023/6/23,2007 SYSTEMS ENGINEERING,17,1.1 THE SYSTEMS POINT OF VIE
20、W,However,interpretation must follow analysis,and meaningful issue formulation 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.,2023/6/23,2007 SYSTEMS ENGINEERING,18,1.1 THE SYSTEMS POINT O
21、F VIEW,System components are often of very 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 build
22、ings.As the system is operating,these 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
23、 that flow or matriculate through the university system.,2023/6/23,2007 SYSTEMS ENGINEERING,19,1.1 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（机制）fo
24、r interaction between professors and students.Grades serve a purpose,intended or not.it is important to understand what purpose,intended and unintended,they serve.,2023/6/23,2007 SYSTEMS ENGINEERING,20,1.1.1Attributes Characterizing Systems,Four Basic Attributes of the System From among many charact
25、eristics,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）,etc.),which may be physical or conceptual,natura
26、l or artificial.,2023/6/23,2007 SYSTEMS ENGINEERING,21,(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 among the units.,1.1.1Four Basic Attributes of the System,2023/6/23,2007 SYSTE
27、MS ENGINEERING,22,EXAMPLE 1.1Logical relationship is determined essentially by definitions and assumptions,such as the relation of production,inventory,and sales in a period:Final inventory（最后清单）=initial inventory+production quantity（生产数量）-sales quantity.EXAMPLE 1.2Institutional relationship（体制关系）is
28、 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 System,2023/6/23,2007 SYSTEMS ENGINEERING,23,1.1.1Four Basic Attributes of the System,(3)Goal-seeking.An actual system as a whole performs a certain functio
29、n or aims at single or multiple objectives.Wherever these objectives are attained at their maximum/minimum levels,system optimization is said to have been performed.For this purpose it is necessary to be able to measure,objectively or subjectively,the degree of attainment of the objectives.An object
30、ive that is measurable by any means is called a goal/target.,2023/6/23,2007 SYSTEMS ENGINEERING,24,EXAMPLE 1.3 A manufacturing system effectively converts resources of production into produced goods(products),attaining an objective that creates high utilities by adding values to the raw materials,re
31、sulting in superior quality,cost and delivery.,2023/6/23,2007 SYSTEMS ENGINEERING,25,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 a
32、ims at organizational objectives such as profit maximization,reasonable rate of return on capital,increase in market share,stable growth,public services(philanthropy),etc.,2023/6/23,2007 SYSTEMS ENGINEERING,26,1.1.1Four Basic Attributes of the System,(4)Adaptability to environment.A specific,factual
33、 system behaves so as to adapt to the change in 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 su
34、ch a way as to be always optimal even under changes in the external environment,is called an adaptive(or cybernetic)system.,2023/6/23,2007 SYSTEMS ENGINEERING,27,If this system possesses dynamic adaptability,approaching a desired state with the least time lag by changing its internal structure and f
35、unctions as the environment changes,it is as self-organizing system.,2023/6/23,2007 SYSTEMS ENGINEERING,28,EXAMPLE 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 economies of scop
36、e.,2023/6/23,2007 SYSTEMS ENGINEERING,29,A 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 conditions,international trends,etc.).The system of
37、ten 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.,2023/6/23,2007 SYSTEMS ENGINEERING,30,1.1.2 Systems Defined,Four Definitions of Systems On the basis of the
38、foregoing considerations,the four essential definitions of systems can now be given as follows(Hitomi,1975).,2023/6/23,2007 SYSTEMS ENGINEERING,31,1.1.2 Systems Defined,(1)Abstract(or basic)definition.On the basis of the first two attributes above,a system is a collection of recognizable units havin
39、g relationships among the units.Under this definition,general system theory has been developed,wherein things are deliberated theoretically,logically,and speculatively.,2023/6/23,2007 SYSTEMS ENGINEERING,32,1.1.2 Systems Defined,(2)Structural(or static)definition.On the basis of all four attributes,
40、a system is a collection of recognizable units having relationships among the units,aiming at specified single or multiple objectives subject to its external environment.,2023/6/23,2007 SYSTEMS ENGINEERING,33,1.1.2 Systems Defined,(3)Transformational(or functional)definition.From the last attribute,
41、the effects of the environment upon the system are inputs(including unforeseen disturbances),and,conversely,the effects in 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
42、 to the environment,whilst seeking to maximize the productivity of the transformation.,2023/6/23,2007 SYSTEMS ENGINEERING,34,1.1.2 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 sp
43、ecified operation is carried out.By performing a complete set of operations according 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.,2023/6/23,2007 SYSTE
44、MS ENGINEERING,35,1.1.3 System Life Cycles,A very important 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 l
45、ife cycle consists of definition of the requirements 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.
46、In all types of system evolution,and as we will discuss,there will be a minimum of three phases:DefinitionDevelopmentDeployment,2023/6/23,2007 SYSTEMS ENGINEERING,36,1.1.3 System Life Cycles,These comprise the essential systems engineering process activities.This life-cycle perspective should also b
47、e associated with a 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.,2023/6/23,2007 SYSTEMS ENGINEERING,37,1.1.3 System Life Cycle
48、s,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 procurement,2023/6/23,2007 SYS
49、TEMS ENGINEERING,38,Introduction to Systems Engineering,1.1 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,2023/6/23,2007 SYSTEMS ENGINEERING,39,1.2 DEFINITIONS OF S
50、YSTEMS 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 may define things according to structure,function,or purpose.Our c
