{{Short description|Examining complex systems as a whole}} <!----> thumb|upright=1.2|right|Depiction of systems thinking about society {{Complex systems}} '''Systems thinking''' is a way of making sense of the complexity of the world by looking at it in terms of wholes and relationships rather than by splitting it down into its parts.<ref name="andersonJohnson1997">Anderson, Virginia, & Johnson, Lauren (1997). ''Systems Thinking Basics: From Concepts to Causal Loops''. Waltham, Mass: Pegasus Comm., Inc.</ref><ref>Magnus Ramage and Karen Shipp. 2009. Systems Thinkers. Springer.</ref> It has been used as a way of exploring and developing effective action in complex contexts,<ref>[https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/285442/12-1043-introduction-to-systems-thinking-gse-seminar.pdf Introduction to Systems thinking]. Report of GSE and GORS seminar. Civil Service Live. 3 July 2012. Government Office for Science.</ref> enabling systems change.<ref name="stem">Sarah York, Rea Lavi, Yehudit Judy Dori, and MaryKay Orgill [https://pubs.acs.org/doi/10.1021/acs.jchemed.9b00261 Applications of Systems Thinking in STEM Education] ''J. Chem. Educ.'' 2019, '''96''', 12, 2742–2751 Publication Date:May 14, 2019 https://doi.org/10.1021/acs.jchemed.9b00261</ref><ref>{{Cite web |title=School of System Change: Why Systems Change? |url=https://schoolofsystemchange.org/systems-change/why-systems-change |access-date=2022-12-06 |website=School of System Change: Learning to lead change in a complex world |language=en}}</ref> Systems thinking draws on and contributes to conceptual systems, systems theory, and the system sciences.<ref name="ackoff">Systemic Thinking 101 [https://www.youtube.com/watch?v=yGN5DBpW93g Russell L Ackoff From Mechanistic to Systemic thinking], also awal street journal [https://www.youtube.com/watch?v=EbLh7rZ3rhU (2016) Systems Thinking Speech by Dr. Russell Ackoff] 1:10:57</ref>
==History== {{Main|Systems theory#History}}
===Ptolemaic system versus the Copernican system=== The term ''system'' has multiple related meanings: Robert Hooke (1674) used it in multiple senses, in his System of the World,<ref name="hooke1674" />{{rp|p.24}} but also in the sense of the Ptolemaic system versus the Copernican system<ref name="marchal" />{{rp|450}} of the relation of the planets to the fixed stars<ref name="voisey">Jon Voisey ''Universe Today'' [https://www.universetoday.com/159885/the-historic-discussion-of-ptolemys-star-catalog/ (14 Oct 2022) Scholarly History of Ptolemy’s Star Catalog Index]</ref> which are cataloged in Hipparchus' and Ptolemy's Star catalog.<ref>Jessica Lightfoot ''Greek, Roman, and Byzantine Studies'' '''57''' (2017) 935–9672017 [https://www.scribd.com/document/397984078/Hipparchus-Commentary-on-Aratus-and-Eudoxus-Introduction-pdf Hipparchus Commentary On Aratus and Eudoxus ]</ref> Hooke's claim was answered in magisterial detail by Newton's (1687) ''Philosophiæ Naturalis Principia Mathematica'', Book three, ''The System of the World''<ref name="systemateMundi">Newton, Isaac (1687) ''Philosophiæ Naturalis Principia Mathematica''</ref>{{rp|Book three}} (that is, ''the system of the world'' is a physical system).<ref name="hooke1674">Hooke, Robert [https://echo.mpiwg-berlin.mpg.de/ECHOdocuView?url=/mpiwg/online/permanent/library/XXTBUC3U/pageimg&pn=25&mode=imagepath (1674) An attempt to prove the motion of the earth from observations ]</ref>
Newton's approach, using dynamical systems continues to this day.<ref name="marchal">{{cite journal | last=Marchal | first=J. H. | title=On the Concept of a System | journal=Philosophy of Science | publisher=[Cambridge University Press, The University of Chicago Press, Philosophy of Science Association] | volume=42 | issue=4 | year=1975 | issn=0031-8248 | jstor=187223 | pages=448–468 | doi=10.1086/288663 | url=http://www.jstor.org/stable/187223 | access-date=2024-05-31| url-access=subscription }} as reprinted in Gerald Midgely (ed.) (2002) ''Systems thinking'' vol '''One'''</ref> In brief, Newton's equations (a system of equations) have methods for their solution.
===Feedback control systems=== [[File:Ideal feedback model.svg|thumb|left|upright=1.5|System output can be controlled with feedback.]] By 1824, the Carnot cycle presented an engineering challenge, which was how to maintain the operating temperatures of the hot and cold working fluids of the physical plant.<ref name="carnot1824">Sadi Carnot (1824) Reflections on the Motive Power of Fire</ref> In 1868, James Clerk Maxwell presented a framework for, and a limited solution to, the problem of controlling the rotational speed of a physical plant.<ref name="jcmaxwell1868">James Clerk Maxwell (1868) On Governors 12 pages</ref> Maxwell's solution echoed James Watt's (1784) centrifugal moderator (denoted as element '''Q''') for maintaining (but not enforcing) the constant speed of a physical plant (that is, ''Q'' represents a moderator, but not a governor, by Maxwell's definition).<ref name="mayr1971">Otto Mayr [https://www.jstor.org/stable/229816 (1971) Maxwell and the Origins of Cybernetics] ''Isis'', Vol. '''62''', No. 4 (Winter, 1971), pp. 424-444 (21 pages)</ref>{{efn|name=stabilityOfSolution|1=A solution to the equations for a dynamical system can be afflicted by instability or oscillation.<ref name="sepulchre">The Royal Society of Edinburgh [https://www.youtube.com/watch?v=U8MFOoa61k4&t=150s (2016) Celebrating Maxwell's Genius and Legacy: Prof Rodolphe Sepulchre]</ref>{{rp|7:33}} The Governor: A corrective action against error can solve the dynamical equation by integrating the error.<ref name="sepulchre" />{{rp|29:44}}<ref name="ÅströmMurray">Karl Johan Åström and Richard M. Murray (2021) [https://press.princeton.edu/books/hardcover/9780691193984/feedback-systems Feedback Systems: An Introduction for Scientists and Engineers, Second Edition]</ref> }}
Maxwell's approach, which linearized the equations of motion of the system, produced a tractable method of solution.<ref name="mayr1971" />{{rp|428–429}} Norbert Wiener identified this approach as an influence on his studies of cybernetics{{efn|name=seeSystemScience |1="cybernetics: ''see system science.''";<ref name="ieee1972" />{{rp|135}} "system science: —the systematized knowledge of systems"<ref name="ieee1972" />{{rp|583}} }} during World War II<ref name="mayr1971" /> and Wiener even proposed treating some subsystems under investigation as black boxes.<ref name="ontologyOfTheEnemy">Peter Galison [https://www.jstor.org/stable/1343893 (1994) The Ontology of the Enemy: Norbert Wiener and the Cybernetic Vision] ''Critical Inquiry'', Vol. '''21''', No. 1 (Autumn, 1994), pp. 228–266 (39 pages) ''JSTOR''</ref>{{rp|242}} Methods for solutions of the systems of equations then become the subject of study, as in feedback control systems, in stability theory, in constraint satisfaction problems, the unification algorithm, type inference, and so forth.
Systems thinking, born from the visionary contributions of theoretical biologist Ludwig von Bertalanffy, computer scientist Jay Forrester, and their contemporaries, reached its zenith in the 1990s with the release of Peter Senge’s seminal work, The Fifth Discipline, a landmark in intellectual exploration.<ref>Why You Need Systems Thinking Now, By: Bansal, Tima; Birkinshaw, Julian. Harvard Business Review. Sep/Oct2025, Vol. 103 Issue 5, p124-133. 10p. </ref>
===Applications=== :"So, how do we change the structure of systems to produce more of what we want and less of that which is undesirable? ... MIT’s Jay Forrester likes to say that the average manager can ... guess with great accuracy where to look for leverage points—places in the system where a small change could lead to a large shift in behavior".<ref name="meadows2008">Donella Meadows, (2008) ''Thinking In Systems: A Primer''</ref>{{rp|146}}— Donella Meadows, (2008) ''Thinking In Systems: A Primer'' p.145{{efn|name=overview|1= Donella Meadows, ''Thinking In Systems: A Primer''<ref name="meadows2008"/><ref name="meadows1977">Donella H. Meadows [https://www.youtube.com/watch?v=XL_lOoomRTA (1977) A Philosophical Look at System Dynamics] 53:18</ref> Overview, in video clips: Chapter 1<ref name="ah1">Ashley Hodgson [https://www.youtube.com/watch?v=XBFpasY2Gd8 Thinking in Systems, Key Ideas (Ch. 1)]</ref> Chapter 2, part 1<ref name="ah2a">Ashley Hodgson [https://www.youtube.com/watch?v=xJLm5uq_QV8&t=37s Thinking in Systems, Ch. 2: Types of System Dynamics 2a]</ref> Chapter 2, part 2<ref name="ah2b">Ashley Hodgson [https://www.youtube.com/watch?v=gwUC7LlqAjI Thinking in Systems, Ch. 2, Part 2: Limiting Factors in Systems 2b]</ref> Chapter 3<ref name="ah3">Ashley Hodgson [https://www.youtube.com/watch?v=2qOc_0DMqaA Thinking in Systems, Ch. 3: Resilience, Self-Organization and Hierarchy 3]</ref> Chapter 4<ref name="ah4">Ashley Hodgson [https://www.youtube.com/watch?v=oHvtERyYvJU Thinking in Systems, Ch. 4: Why Systems Surprise Us 4]</ref> Chapter 5<ref name="ah5">Ashley Hodgson [https://www.youtube.com/watch?v=BYSFvq8sr7A Thinking in Systems, Ch. 5: System Traps 5]</ref> Chapter 6<ref name="ah6">Ashley Hodgson [https://www.youtube.com/watch?v=9qL4KxqbrFM Thinking in Systems, Ch. 6: Leverage Points in Systems 6]</ref> Chapter 7<ref name="ah7">Ashley Hodgson [https://www.youtube.com/watch?v=q8QYU2JL8no Thinking in Systems, Ch. 7: Living with Systems 7]</ref> <!--ref name= > [ ]</ref-->}}
==Characteristics== thumb|upright=0.8|System boundary in context thumb|upright=0.8|System input and output allows exchange of energy and information across boundary. {{anchor|System}}{{quote|...What is a system? A system is a set of things ... interconnected in such a way that they produce their own pattern of behavior over time. ... But the system’s response to these forces is characteristic of itself, and that response is seldom simple in the real world|Donella Meadows<ref name="meadows2008" />{{rp|2}}}} {{quote|[a system] is "an integrated whole even though composed of diverse, interacting, specialized structures and subjunctions"|IEEE (1972)<ref name="ieee1972">IEEE (1972) Standard Dictionary of Electrical and Electronics Terms</ref>{{rp|582}}}}"a system is a collection of things that are interconnected and interdependent from which stuff emerges"<ref name=":0">{{Cite book |last=Walls & Flach |first=Adam & John |title=Do systems exist? A conversation |date=26 April 2025 |publisher=amazon |isbn=979-8280557635 |edition=1st |location=UK |pages=1 |language=English}}</ref>
-Walls & Flach (2025) <ref name=":0" /> *{{anchor|subsystem}}Subsystems serve as part of a larger system, but each comprises a system in its own right. Each frequently can be described reductively, with properties obeying its own laws, such as Newton's System of the World, in which entire planets, stars, and their satellites can be treated, sometimes in a scientific way as dynamical systems, entirely mathematically, as demonstrated by Johannes Kepler's equation (1619) for the orbit of Mars before Newton's ''Principia'' appeared in 1687. *{{anchor|black box}}Black boxes are subsystems whose operation can be characterized by their inputs and outputs, without regard to further detail.<ref name="meadows2008" />{{rp|87–88}}<ref name="bbw">Wiener, Norbert; ''Cybernetics: Or the Control and Communication in the Animal and the Machine'', MIT Press, 1961, ISBN 0-262-73009-X, page xi</ref>
===Particular systems=== *Political systems were recognized as early as the millennia before the common era.<ref name="aristotlePolitics">Aristotle, ''Politics''</ref><ref>JS Maloy (2009) [https://www.jstor.org/stable/40208102 The Aristotelianism of Locke's Politics] ''Journal of the History of Ideas'', Vol. '''70''', No. 2 (April 2009), pp. 235–257 (23 pages)</ref> *Biological systems were recognized in Aristotle's lagoon ca. 350 BCE.<ref>Aristotle, History of Animals</ref><ref name="Lennox">{{cite web |last1=Lennox |first1=James |title=Aristotle's Biology |url=http://plato.stanford.edu/entries/aristotle-biology/ |website=Stanford Encyclopedia of Philosophy |publisher=Stanford University |access-date=28 November 2014 |date=27 July 2011}}</ref> *Economic systems were recognized by 1776.<ref name="smith76">Adam Smith [https://standardebooks.org/ebooks/adam-smith/the-wealth-of-nations/text (1776) ''The Wealth of Nations''] Book IV refers to commercial, and mercantile systems, as well as to systems of political enonomy</ref> *Social systems were recognized by the 19th and 20th centuries of the common era.<ref>Max Weber, The Protestant Ethic and the Spirit of Capitalism</ref><ref>Talcott Parsons, The Structure of Social Action</ref> *Radar systems were developed in World War II in subsystem fashion; they were made up of transmitter, receiver, power supply, and signal processing subsystems, to defend against airborne attacks.<ref>MIT Radiation Laboratory, MIT Radiation Laboratory Series, 28 volumes</ref> *Dynamical systems of ordinary differential equations were shown to exhibit stable behavior given a suitable Lyapunov control function by Aleksandr Lyapunov in 1892.<ref name="pates">Richard Pates [https://www.youtube.com/watch?v=uXAx_641FPM (2021) What is a Lyapunov function]</ref> *Thermodynamic systems were treated as early as the eighteenth century, in which it was discovered that heat could be created without limit, but that for closed systems, laws of thermodynamics could be formulated.<ref name="beingatoBecoming">{{cite book | authorlink=Ilya Prigogine|last=Prigogine | first=Ilya | year=1980 | title=From Being To Becoming | publisher=Freeman | isbn=0-7167-1107-9 | url-access=registration | url=https://archive.org/details/frombeingtobecom00ipri }} 272 pages.</ref> Ilya Prigogine (1980) has identified situations in which systems far from equilibrium can exhibit stable behavior;<ref name="G&P1971">Glansdorff, P., Prigogine, I. (1971). [https://books.google.com/books?id=vf9QAAAAMAAJ ''Thermodynamic Theory of Structure, Stability and Fluctuations''], London: Wiley-Interscience {{ISBN|0-471-30280-5}}</ref> once a Lyapunov function has been identified, future and past can be distinguished, and scientific activity can begin.<ref name="beingatoBecoming" />{{rp|212–213}}
===Systems far from equilibrium=== {{anchor|Resilience}} Living systems are resilient,<ref name="ah3" /> and are far from equilibrium.<ref name="meadows2008"/>{{rp|Ch.3}}<ref name="G&P1971" /> Homeostasis is the analog to equilibrium, for a living system; the concept was described in 1849, and the term was coined in 1926.<ref name="wotb">{{cite book |first=W.B. |last=Cannon |author-link=Walter Bradford Cannon |title=The Wisdom of the Body |pages=177–201 |year=1932 |publisher=W. W. Norton |location=New York}}</ref><ref name="cannon">{{cite book |language=fr |first=W. B. |last=Cannon |author-link=Walter Bradford Cannon |chapter=Physiological regulation of normal states: some tentative postulates concerning biological homeostatics |editor=A. Pettit|title=A Charles Riches amis, ses collègues, ses élèves |page=91 |publisher=Les Éditions Médicales |location=Paris |year=1926}}</ref>
{{anchor|Self-organization}} Resilient systems are self-organizing;<ref name="ah3" />{{efn|name=klirSystemScience |1=Abstract: [https://link.springer.com/chapter/10.1007/978-1-4899-0718-9_1 "An inevitable prerequisite for this book, as implied by its title, is a presupposition that systems science is a legitimate field of scientific inquiry. It is self-evident that I, as the author of this book, consider this presupposition valid. Otherwise, clearly, I would not conceive of writing the book in the first place"]. —George J. Klir, "What Is Systems Science?" from ''Facets of Systems Science'' (1991) }}<ref name="meadows2008" />{{rp|Ch.3}}<ref>H T Odum [https://www.science.org/doi/10.1126/science.242.4882.1132 (25 Nov 1988) Self-Organization, Transformity and Information] ''Science'' Vol '''242''', Issue 4882 pp. 1132–1139 as reprinted by Gerald Midgley ed. (2002), ''Systems Thinking'' vol ''2''</ref>
{{anchor|Hierarchy}} The scope of functional controls is hierarchical, in a resilient system.<ref name="ah3" /><ref name="meadows2008" />{{rp|Ch.3}}
==Frameworks and methodologies== Frameworks and methodologies for systems thinking include: * Critical systems heuristics:<ref name="ulrich" >{{cite web|author=Werner Ulrich|url=https://wulrich.com/downloads/ulrich_2005f.pdf|date=1987|title=A Brief Introduction to Critical Systems Heuristics (CSH)}}</ref> in particular, there can be twelve boundary categories for the systems when organizing one's thinking and actions. * Critical systems thinking, including the E P I C approach. * DSRP, a framework for systems thinking that attempts to generalise all other approaches. * Ontology engineering of representation, formal naming and definition of categories, and the properties and the relations between concepts, data, and entities. * Soft systems methodology, including the CATWOE approach and rich pictures. * Systemic design, for example using the double diamond approach. * System dynamics of stocks, flows, and internal feedback loops. * Viable system model: uses 5 subsystems.
==See also== {{Portal|Systems science}} * {{annotated link|Biogeochemistry}} * {{annotated link|Conceptual systems}} * {{annotated link|Management cybernetics}} * {{annotated link|Operations research}} * {{annotated link|Systems engineering}} * {{annotated link|Industrial ecology}} * {{annotated link|Feedback loop}}
==Notes== {{Notelist}}
==References== {{Reflist}}
===Sources=== * Adam Walls & John Flach (2024) "Do systems exist? A conversation: A short discussion on founding concepts behind general systems theory and soft systems. * Russell L. Ackoff (1968) "General Systems Theory and Systems Research Contrasting Conceptions of Systems Science." in: ''Views on a General Systems Theory: Proceedings from the Second System Symposium'', Mihajlo D. Mesarovic (ed.). * A.C. Ehresmann, J.-P. Vanbremeersch (1987) [https://www.sciencedirect.com/science/article/abs/pii/S009282408780033 Hierarchical evolutive systems: A mathematical model for complex systems]" ''Bulletin of Mathematical Biology'' Volume '''49''', Issue 1, Pages 13–50 * NJTA Kramer & J de Smit (1977) ''Systems thinking: Concepts and Notions'', Springer. 148 pages * A. H. Louie (November 1983) "[https://link.springer.com/article/10.1007/BF02458830 Categorical system theory]" ''Bulletin of Mathematical Biology'' volume '''45''', pages 1047–1072 * DonellaMeadows.org [https://donellameadows.org/systems-thinking-resources/ Systems Thinking Resources] * Gerald Midgley (ed.) (2002) ''Systems Thinking'', SAGE Publications. 4 volume set: 1,492 pages [https://uk.sagepub.com/en-gb/eur/systems-thinking/book225004#contents List of chapter titles] <!--* Ross D. Arnold, Jon P. Wade ''[https://www.sciencedirect.com/science/article/pii/S1877050915002860?via%3Dihub A Definition of Systems Thinking: A Systems Approach]''--> * Robert Rosen. (1958) “[http://www.few.vu.nl/~rplanque/Onderwijs/MathBio/PapersForProject/Rosen.pdf The Representation of Biological Systems from the Standpoint of the Theory of Categories]". ''Bull. math. Biophys.'' '''20''', 317–342. * Peter Senge, (1990) ''The Fifth Discipline''
{{Systems}} {{Authority control}}
Category:Systems thinking Category:Cybernetics Category:Systems science Category:Systems theory