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.[1][2] It has been used as a way of exploring and developing effective action in complex contexts,[3] enabling
systems change.[4][5] Systems thinking draws on and contributes to
systems theory and the
system sciences.[6]
The term system is
polysemic: Robert Hooke (1674) used it in multiple senses, in his System of the World,[7]: p.24 but also in the sense of the
Ptolemaic system versus the
Copernican system[8]: 450 of the relation of the planets to the fixed stars[9] which are cataloged in Hipparchus and Ptolemy's Star catalog.[10] Hooke's claim was answered in magisterial detail by Newton's (1687) Philosophiæ Naturalis Principia Mathematica, Book three, The System of the World[11]: Book three (that is, the system of the world is a
physical system).[7]
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.[12] 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.[13] 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).[14][a]
"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".[19]: 146 —
Donella Meadows, (2008) Thinking In Systems: A Primer p.145 [c]
Characteristics
"...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[19]: 2
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.
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.[39]Ilya Prigogine (1980) has identified situations in which systems far from equilibrium can exhibit stable behavior;[40] once a Lyapunov function has been identified, future and past can be distinguished, and scientific activity can begin.[39]: 212–213
Systems far from equilibrium
Living systems are resilient,[24] and are far from equilibrium.[19]: Ch.3 [40]Homeostasis is the analog to equilibrium, for a living system; the concept was described in 1849, and the term was coined in 1926.[41][42]
The scope of functional controls is hierarchical, in a resilient system.[24][19]: Ch.3
Frameworks and methodologies
Frameworks and methodologies for systems thinking include:
Critical systems heuristics:[44] in particular, there can be twelve boundary categories for the systems when organizing one's thinking and actions.[44]
Ontology engineering of representation, formal naming and definition of categories, and the properties and the relations between concepts, data, and entities.
^A solution to the equations for a dynamical system can be afflicted by instability or oscillation.[15]: 7:33 The Governor: A corrective action against error can solve the dynamical equation by integrating the error.[15]: 29:44 [16]
^"cybernetics: see system science.";[17]: 135 "system science: —the systematized knowledge of
systems"[17]: 583
^Donella Meadows, Thinking In Systems: A Primer[19][20] Overview, in video clips: Chapter 1[21] Chapter 2, part 1[22] Chapter 2, part 2[23] Chapter 3[24] Chapter 4[25] Chapter 5[26] Chapter 6[27] Chapter 7[28]
^
abJ H Marchal
(Dec 1975) On the concept of a systemPhilosophy of Science, Vol. 42, No. 4 (December 1975), pp. 448–468 (21 pages) as reprinted in Gerald Midgely (ed.) (2002) Systems thinking vol One
^Cannon, W.B. (1932). The Wisdom of the Body. New York: W. W. Norton. pp. 177–201.
^Cannon, W. B. (1926). "Physiological regulation of normal states: some tentative postulates concerning biological homeostatics". In A. Pettit (ed.). A Charles Riches amis, ses collègues, ses élèves (in French). Paris: Les Éditions Médicales. p. 91.
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.).