System

Asystemis a group of interacting or interrelated elements that act according to a set of rules to form a unified whole.^[1]A system, surrounded and influenced by itsenvironment,is described by its boundaries,structureand purpose and is expressed in its functioning. Systems are the subjects of study ofsystems theoryand othersystems sciences.

Systems have several common properties and characteristics, including structure, function(s), behavior and interconnectivity.

Etymology

The termsystemcomes from theLatinwordsystēma,in turn fromGreekσύστημαsystēma:"whole concept made of several parts or members, system", literary "composition".^[2]^[3]

History

In the 19th century, the French physicistNicolas Léonard Sadi Carnot,who studiedthermodynamics,pioneered the development of the concept of asystemin thenatural sciences.In 1824, he studied the system which he called theworking substance(typically a body of water vapor) insteam engines,in regard to the system's ability to do work when heat is applied to it. The working substance could be put in contact with either a boiler, a cold reservoir (a stream of cold water), or a piston (on which the working body could do work by pushing on it). In 1850, the German physicistRudolf Clausiusgeneralized this picture to include the concept of thesurroundingsand began to use the termworking bodywhen referring to the system.

The biologistLudwig von Bertalanffybecame one of the pioneers of thegeneral systems theory.In 1945 he introducedmodels, principles, and laws that apply to generalized systems or their subclasses, irrespective of their particular kind, the nature of their component elements, and the relation or 'forces' between them.^[4]

In the late 1940s and mid-50s,Norbert WienerandRoss Ashbypioneered the use of mathematics to study systems ofcontrolandcommunication,calling itcybernetics.^[5]^[6]

In the 1960s,Marshall McLuhanapplied general systems theory in an approach that he called a field approach andfigure/ground analysis,to the study ofmedia theory.^[7]^[8]

In the 1980s,John Henry Holland,Murray Gell-Mannand others coined the termcomplex adaptive systemat the interdisciplinarySanta Fe Institute.^{[citation needed]}

Concepts

Environment and boundaries

Systems theoryviews the world as acomplex systemof interconnected parts. One scopes a system by defining itsboundary;this means choosing which entities are inside the system and which are outside—part of theenvironment.One can make simplified representations (models) of the system in order to understand it and to predict or impact its future behavior. These models may define the structure and behavior of the system.

Natural and human-made systems

There are natural and human-made (designed) systems. Natural systems may not have an apparent objective but their behavior can be interpreted as purposeful by an observer. Human-made systems are made with various purposes that are achieved by some action performed by or with the system. The parts of a system must be related; they must be "designed to work as a coherent entity" —otherwise they would be two or more distinct systems.

*Open systems*have input and output flows, representing exchanges of matter, energy or information with their surroundings.

Theoretical framework

Most systems areopen systems,exchanging matter and energy with their respective surroundings; like a car, acoffeemaker,orEarth.Aclosed systemexchanges energy, but not matter, with its environment; like a computer or the projectBiosphere 2.Anisolated systemexchanges neither matter nor energy with its environment. A theoretical example of such a system is theUniverse.

Process and transformation process

Anopen systemcan also be viewed as a bounded transformation process, that is, ablack boxthat is a process or collection of processes that transform inputs into outputs. Inputs are consumed; outputs are produced. The concept of input and output here is very broad. For example, an output of a passenger ship is the movement of people from departure to destination.

System model

A system comprisesmultiple views.Human-made systems may have such views as concept,analysis,design,implementation,deployment, structure, behavior, input data, and output data views. Asystem modelis required to describe and represent all these views.

Systems architecture

A systems architecture, using one single integrated model for the description of multiple views, is a kind of system model.

Subsystem

Asubsystemis a set of elements, which is a system itself, and a component of a larger system. The IBM MainframeJob Entry Subsystemfamily (JES1,JES2,JES3,and theirHASP/ASPpredecessors) are examples. The mainelementsthey have in common are the components that handle input, scheduling, spooling and output; they also have the ability to interact with local and remote operators.

A subsystem description is a system object that contains information defining the characteristics of an operating environment controlled by the system.^[9]The data tests are performed to verify the correctness of the individual subsystem configuration data (e.g. MA Length, Static Speed Profile,…) and they are related to a single subsystem in order to test its Specific Application (SA).^[10]

Analysis

There are many kinds of systems that can be analyzed bothquantitativelyandqualitatively.For example, in an analysis of urbansystems dynamics,A. W. Steiss defined five intersecting systems, including the physical subsystem and behavioral system. For sociological models influenced by systems theory,^[11]Kenneth D. Baileydefined systems in terms ofconceptual,concrete,and abstract systems, eitherisolated,closed,oropen.^[12]Walter F. Buckleydefined systems in sociology in terms ofmechanical,organic,andprocess models.^[13]Bela H. Banathycautioned that for any inquiry into a system understanding its kind is crucial, and definednaturalanddesigned,i. e. artificial, systems.^[14]For example, natural systems includesubatomicsystems,living systems,theSolar System,galaxies,and theUniverse,while artificial systems include man-made physical structures, hybrids of natural and artificial systems, and conceptual knowledge. The human elements of organization and functions are emphasized with their relevant abstract systems and representations.

Artificial systems inherently have a major defect: they must be premised on one or more fundamental assumptions upon which additional knowledge is built. This is in strict alignment withGödel's incompleteness theorems.The Artificial system can be defined as a "consistent formalized system which contains elementary arithmetic".^[15]These fundamental assumptions are not inherently deleterious, but they must by definition be assumed as true, and if they are actually false then the system is not as structurally integral as is assumed (i.e. it is evident that if the initial expression is false, then the artificial system is not a "consistent formalized system" ). For example, ingeometrythis is very evident in the postulation oftheoremsand extrapolation of proofs from them.

George J. Klirmaintained that no "classification is complete and perfect for all purposes", and defined systems as abstract, real, andconceptual physical systems,bounded andunbounded systems,discrete to continuous, pulse tohybrid systems,etc. The interactions between systems and their environments are categorized as relatively closed andopen systems.^[16]Important distinctions have also been made betweenhardsystems—–technical in nature and amenable to methods such assystems engineering,operations research, and quantitative systems analysis—andsoftsystems that involve people and organizations, commonly associated with concepts developed byPeter ChecklandandBrian Wilsonthroughsoft systems methodology(SSM) involving methods such asaction researchand emphasis of participatory designs.^[17]Where hard systems might be identified as morescientific,the distinction between them is often elusive.

Economic system

An economic system is asocial institutionwhich deals with theproduction,distributionandconsumptionofgoodsandservicesin a particularsociety.The economic system is composed ofpeople,institutionsand their relationships to resources, such as theconventionofproperty.It addresses the problems ofeconomics,like the allocation and scarcity of resources.

The international sphere of interacting states is described and analyzed in systems terms by several international relations scholars, most notably in theneorealist school.This systems mode of international analysis has however been challenged by other schools of international relations thought, most notably theconstructivist school,which argues that an over-large focus on systems and structures can obscure the role of individual agency in social interactions. Systems-based models of international relations also underlie the vision of the international sphere held by theliberal institutionalistschool of thought, which places more emphasis on systems generated by rules and interaction governance, particularly economic governance.

Information and computer science

Incomputer scienceandinformation science,aninformation systemis a hardware system,software system,or combination, which hascomponentsas its structure and observableinter-process communicationsas its behavior.

There are systems of counting, as withRoman numerals,and various systems for filing papers, or catalogs, and various library systems, of which theDewey Decimal Classificationis an example. This still fits with the definition of components that are connected together (in this case to facilitate the flow of information).

System can also refer to a framework, akaplatform,be itsoftwareor hardware, designed to allow software programs to run. A flaw in a component or system can cause the component itself or an entire system to fail to perform its required function, e.g., an incorrectstatementordata definition.^[18]

Engineering and physics

Inengineeringandphysics,a physical system is the portion of the universe that is being studied (of which athermodynamic systemis one major example). Engineering also has the concept of a system referring to all of the parts and interactions between parts of a complex project.Systems engineeringis the branch of engineering that studies how this type of system should be planned, designed, implemented, built, and maintained.^[18]

Sociology, cognitive science and management research

Social andcognitive sciencesrecognize systems in models of individual humans and in human societies. They include human brain functions and mental processes as well as normative ethics systems and social and cultural behavioral patterns.

Inmanagement science,operations researchandorganizational development,human organizations are viewed asmanagement systemsof interacting components such as subsystems or system aggregates, which are carriers of numerous complexbusiness processes(organizational behaviors) and organizational structures. Organizational development theoristPeter Sengedeveloped the notion of organizations as systems in his bookThe Fifth Discipline.^[19]

Organizational theoristssuch asMargaret Wheatleyhave also described the workings of organizational systems in new metaphoric contexts, such asquantum physics,chaos theory,and theself-organization of systems.^[20]

Pure logic

There is also such a thing as alogical system.An obvious example is the calculus developed simultaneously byLeibnizandIsaac Newton.Another example isGeorge Boole's Boolean operators. Other examples relate specifically to philosophy, biology, or cognitive science.Maslow's hierarchy of needsapplies psychology to biology by using pure logic. Numerous psychologists, includingCarl JungandSigmund Freuddeveloped systems that logically organize psychological domains, such as personalities, motivations, or intellect and desire.

Strategic thinking

In 1988, military strategist,John A. Warden IIIintroduced theFive Ring Systemmodel in his book,The Air Campaign,contending that any complex system could be broken down into five concentric rings. Each ring—leadership, processes, infrastructure, population and action units—could be used to isolate key elements of any system that needed change. The model was used effectively byAir Forceplanners in theIran–Iraq War.^[21]^[22]^[23]In the late 1990s, Warden applied his model to business strategy.

References

^"Definition ofsystem".Merriam-Webster.Springfield, MA, USA.Archivedfrom the original on 2017-06-05.Retrieved2019-01-16.
^"σύστημα"Archived2021-01-28 at theWayback Machine,Henry George Liddell, Robert Scott,A Greek–English Lexicon,on Perseus Digits Library.
^Definitionen von "System" (1572–2002)by Roland Müller, (most in German).
^1945,Zu einer allgemeinen Systemlehre,Blätter für deutsche Philosophie, 3/4. (Extract in: Biologia Generalis, 19 (1949), 139–164.
^ 1948,Cybernetics: Or the Control and Communication in the Animal and the Machine.Paris, France: Librairie Hermann & Cie, and Cambridge, MA: MIT Press.Cambridge, MA: MIT Press.
^1956.An Introduction to Cybernetics Archived2023-05-17 at theWayback Machine,Chapman & Hall.
^McLuhan, Marshall(1964).Understanding Media: The Extensions of Man.McGraw-Hill Education. reissued by Gingko Press, 2003.ISBN 978-1-58423-073-1.
^McLuhan, Marshall;Fiore, Quentin(1967).The Medium Is the Massage: An Inventory of Effects (1st ed.).Random House. Reissued by Gingko Press, 2001.ISBN 978-1-58423-070-0.
^"Work management subsystem concepts: Subsystem description".www.ibm.com.Retrieved2024-09-26.
^European Committee for Electrotechnical Standardization (CENELEC) - EN 50128.Brussels, Belgium: CENELEC. 2011. pp. Table A.11 – Data Préparation Techniques (8.4).
^Steiss, 1967, pp. 8–18.
^Bailey, 1994.
^Buckley, 1967.
^Banathy, 1997.
^K.Gödel, 1931.
^Klir, 1969, pp. 69–72.
^Checkland, 1997; Flood, 1999.
^^a ^b"ISTQB Standard glossary of terms used in Software Testing".Archived fromthe originalon 5 November 2018.Retrieved15 March2019.
^Senge, P. M. (1990).The Fifth Discipline: The Art and Practice of the Learning Organization.Doubleday/Currency.ISBN 9780385260947.
^"A New Story for a New Time".Retrieved2024-03-12.
^Warden, John A. III(1988).The Air Campaign: Planning for Combat.Washington, D.C.: National Defense University Press.ISBN 978-1-58348-100-4.
^Warden, John A. III (September 1995)."Chapter 4: Air theory for the 21st century".Battlefield of the Future: 21st Century Warfare Issues.United States Air Force. Archived fromthe original(inAir and Space Power Journal)on July 4, 2011.RetrievedDecember 26,2008.
^Warden, John A. III (1995)."Enemy as a System".Airpower Journal.Spring (9): 40–55. Archived fromthe originalon 2009-01-13.Retrieved2009-03-25.

Bibliography

Alexander Backlund (2000). "The definition of system".In:KybernetesVol. 29 nr. 4, pp. 444–451.
Kenneth D. Bailey(1994).Sociology and the New Systems Theory: Toward a Theoretical Synthesis.New York: State of New York Press.
Bela H. Banathy(1997).A Taste of Systemicsat theWayback Machine(archived 2023-03-07), ISSS The Primer Project.
Walter F. Buckley(1967).Sociology and Modern Systems Theory,New Jersey: Englewood Cliffs.
Peter Checkland(1997).Systems Thinking, Systems Practice.Chichester: John Wiley & Sons, Ltd.
Michel Crozier,Erhard Friedberg (1981).Actors and Systems,Chicago University Press.
Robert L. Flood(1999).Rethinking the Fifth Discipline: Learning within the unknowableat theWayback Machine(archived 2019-02-25). London: Routledge.
George J. Klir(1969). Approach to General Systems Theory, 1969.
Brian Wilson(1980).Systems: Concepts, methodologies and Applications,John Wiley.
Brian Wilson (2001).Soft Systems Methodology—Conceptual model building and its contribution,J.H.Wiley.
Beynon-Davies, P. (2009).Business Information + Systems.Palgrave, Basingstoke.ISBN 978-0-230-20368-6.

External links

Definitions of Systems and Modelsby Michael Pidwirny, 1999–2007.

[merriam-webster-system-1] "Definition ofsystem".Merriam-Webster.Springfield, MA, USA.Archivedfrom the original on 2017-06-05.Retrieved2019-01-16.

[:1-2] "σύστημα"Archived2021-01-28 at theWayback Machine,Henry George Liddell, Robert Scott,A Greek–English Lexicon,on Perseus Digits Library.

[3] Definitionen von "System" (1572–2002)by Roland Müller, (most in German).

[Bertalanfy1945-4] 1945,Zu einer allgemeinen Systemlehre,Blätter für deutsche Philosophie, 3/4. (Extract in: Biologia Generalis, 19 (1949), 139–164.

[Wiener1948-5] 1948,Cybernetics: Or the Control and Communication in the Animal and the Machine.Paris, France: Librairie Hermann & Cie, and Cambridge, MA: MIT Press.Cambridge, MA: MIT Press.

[Ashby1950-6] 1956.An Introduction to Cybernetics Archived2023-05-17 at theWayback Machine,Chapman & Hall.

[7] McLuhan, Marshall(1964).Understanding Media: The Extensions of Man.McGraw-Hill Education. reissued by Gingko Press, 2003.ISBN 978-1-58423-073-1.

[8] McLuhan, Marshall;Fiore, Quentin(1967).The Medium Is the Massage: An Inventory of Effects (1st ed.).Random House. Reissued by Gingko Press, 2001.ISBN 978-1-58423-070-0.

[9] "Work management subsystem concepts: Subsystem description".www.ibm.com.Retrieved2024-09-26.

[10] European Committee for Electrotechnical Standardization (CENELEC) - EN 50128.Brussels, Belgium: CENELEC. 2011. pp. Table A.11 – Data Préparation Techniques (8.4).

[11] Steiss, 1967, pp. 8–18.

[12] Bailey, 1994.

[13] Buckley, 1967.

[14] Banathy, 1997.

[15] K.Gödel, 1931.

[16] Klir, 1969, pp. 69–72.

[17] Checkland, 1997; Flood, 1999.

[:0-18] "ISTQB Standard glossary of terms used in Software Testing".Archived fromthe originalon 5 November 2018.Retrieved15 March2019.

[19] Senge, P. M. (1990).The Fifth Discipline: The Art and Practice of the Learning Organization.Doubleday/Currency.ISBN 9780385260947.

[20] "A New Story for a New Time".Retrieved2024-03-12.

[21] Warden, John A. III(1988).The Air Campaign: Planning for Combat.Washington, D.C.: National Defense University Press.ISBN 978-1-58348-100-4.

[22] Warden, John A. III (September 1995)."Chapter 4: Air theory for the 21st century".Battlefield of the Future: 21st Century Warfare Issues.United States Air Force. Archived fromthe original(inAir and Space Power Journal)on July 4, 2011.RetrievedDecember 26,2008.

[23] Warden, John A. III (1995)."Enemy as a System".Airpower Journal.Spring (9): 40–55. Archived fromthe originalon 2009-01-13.Retrieved2009-03-25.

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v t e Systems engineering
Subfields	Aerospace engineering Biological systems engineering Cognitive systems engineering Configuration management Earth systems engineering and management Electrical engineering Enterprise systems engineering Health systems engineering Performance engineering Reliability engineering Safety engineering Sociocultural Systems Engineering
Processes	Requirements engineering Functional specification System integration Verification and validation Design review System of systems engineering
Concepts	Business process Fault tolerance System System lifecycle V-Model Systems development life cycle
Tools	Decision-making Function modelling IDEF Optimization Quality function deployment System dynamics Systems Modeling Language Systems analysis Systems modeling Work breakdown structure
People	James S. Albus Ruzena Bajcsy Benjamin S. Blanchard Wernher von Braun Kathleen Carley Harold Chestnut Wolt Fabrycky Barbara Grosz Arthur David Hall III Derek Hitchins Robert E. Machol Radhika Nagpal Simon Ramo Joseph Francis Shea Katia Sycara Manuela M. Veloso John N. Warfield
Related fields	Control engineering Computer engineering Industrial engineering Operations research Project management Quality management Risk management Software engineering
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