General system theory after von Bertalanffy
Copyright 2017 Graham Berrisford. One of about 300 papers at http://avancier.website. Last updated 02/03/2018 21:00
The role of enterprise architects is to observe baseline systems, envisage target systems, and describe both.
So, you might assume it is universally agreed what a "system" is; but this is far from the case.
This article introduces von Bertlanffy’s early ideas of general system theory.
Other papers add many more system theory terms and concepts.
This section recaps a few of the ideas in Introducing System Ideas with reference to von Bertalanffy, and adds a few ideas of his own.
Ludwig von Bertalanffy (1901-1972) was a biologist who promoted the idea of a general system theory in the middle of the 20th century.
His aim was to discover patterns and elucidate principles common to systems in every discipline, at every level of nesting.
He looked for concepts and principles applicable broadly, rather than to one discipline or domain of knowledge.
In “General System theory: Foundations, Development, Applications” (1968), he wrote:
“There exist models, principles, and laws that apply to generalized systems or their subclasses, irrespective of their particular kind, the nature of their component elements.” Bertalanffy
Bertalanffy used the term "system" to mean an entity in which the parts behave holistically.
“General System Theory… is a general science of wholeness… systems [are] not understandable by investigation of their respective parts in isolation.” Bertalanffy
His interest was in how parts interact and cooperate to enable the whole, or serve the whole.
Holistic view: a description of how parts relate, interact or cooperate in a whole.
E.g. a description of how the muscles of the human heart interact.
Note: when you study a subsystem in isolation, it is the whole system of interest to you.
When you study how two systems are related, they become parts of a wider whole.
It is axiomatic that an event that is external to a smaller system is internal to a larger system
Also, the emergent properties of a small system are ordinary properties of any larger system it is a part of.
Emergent property: a behavior or structure of a whole that depends on interactions between its parts.
E.g. the forward motion of a cyclist on a bicycle, or the V shape of a flight of geese.
Note that emergent does not mean unwanted or unexpected.
If you had never seen a bicycle ridden before, the forward motion of bicycle and rider would be a surprise.
However, that motion was wanted and expected by the bicycle designer.
The requirements for any designed system must include emergent properties.
Reductionist view: identifying the parts of a whole, naming or describing parts without considering how the parts are related in the whole.
E.g. listing the organs and limbs of the body without relating them.
Or analysing and describing the heart without reference to the lungs.
Bertalanffy deprecated reductionism (studying organs in isolation) and promoted holism (studying how organs cooperate to the benefit of the body).
However, the scope of the "whole" is a matter of choice; and so too is the granularity of a “part”.
In practice, people flip between holistic and reductionist views of things.
So, the definitions above allow that systems can be nested and systems thinking can be recursive.
Read Holism and emergent properties for more.
With his background in biology, von Bertalanffy wrote of a concept he called organicism.
Organicism: the idea that systems are describable at multiple hierarchical levels.
He meant a system may be decomposable into subsystems, and/or composable (with others) into larger systems.
Ackoff arranged aims, behaviors and systems in hierarchical structures, using different words at different levels.
It can be convenient to do this, as illustrated in this table
But pinning different words to different levels of continuous decomposition is arbitrary.
And trying to do it can obscure the general nature of system theory.
The concepts are the same at whatever level of system composition you choose to model.
A process is process: a sequence of actions that may refer to system state, include choices and produce outcomes.
A choice is a choice: whether it is made by strict or fuzzy logic, deterministically or by free will (if you consider those to be incompatible).
Read Introducing System Ideas for more on ideas traceable to von Bertlanffy’s writings, including:
· Systems of systems
· Goal directedness
· Communication via information flows
· Homeostatic and progressive systems.
Today’s general system theorist need not embrace all Bertalanffy wrote.
Some ideas von Bertalanffy supposed to be general don’t appear in this update of GST.
Hierarchy is not essential to all systems.
The designer of a human or computer activity system has to strike a balance between centralisation and distribution of process control.
Centralisation implies some kind of management hierarchy; and distribution implies its literal opposite – an anarchy, or a network.
Read Hierarchical and network organisations for more.
The term implies complicated in some way, but there no agreed measure of complexity.
Bertalanffy said system elements are discrete, can be classified into kinds, can be counted, and the relationships between them can be described.
“In dealing with complexes of 'elements', three different kinds of distinction may be made: according to their number; their species; the relations of elements.” von Bertalanffy
To measure complexity, should we measure the concrete system or its abstract system description?
The only way to measure the complexity of a system is by reference to a description of it structures and behaviors.
Suppose we were able to count element kinds and relationships in an abstract system description
How to combine those numbers into an overall complexity measure?
Scores of complexity measures have been proposed.
E.g. my own: complexity = the number of event/state combinations * the average procedural complexity of the rules applied to them.
The term complex is sometimes used to mean a non-linear or stochastic system.
But simple deterministic systems can behave in non-linear or stochastic ways.
So, a complex entity may be seen as a simple system.
Every hamburger is infinitely complex; but the recipe for a hamburger is a relatively simple abstract system description.
Every real-world US government is infinitely complex; but the US constitution is relatively simple abstract system description.
A US government can be called a system where and in so far as it realises the US constitution.
But most of the time, government actors are choosing and performing activities in ad hoc ways not explicitly described in the constitution.
As a social entity, the US government is infinitely complex; as a system it is relatively simple.
Read Complexity for more.
Bertalanffy stretched his ideas into proposals about human psychology and the meaning of life.
“Life is not comfortable setting down in pre-ordained grooves of being; at its best, it is élan vital, inexorably driven towards higher forms of existence”.
It is possible Bertalanffy borrowed the idea of inexorable progress from Marxism.
The fact is, inexorable progress is not what one finds in nature.
Read Marxism, system theory and EA for a critique of this idea.
He eventually committed to this book (1968) in which he said GST brings us “nearer the goal of the unity of science”.
The quotes below are drawn from selected passages, which you can find on this web page.
“There exist models, principles, and laws that apply to generalized systems or their subclasses, irrespective of their particular kind, the nature of their component elements.”
“conceptions appear in contemporary science that are concerned with what is somewhat vaguely termed 'wholeness'.
I.e. problems of organization, phenomena not resolvable into local events, dynamic interactions manifest in difference of behavior of parts when isolated or in a higher configuration, etc.
In short, 'systems' of various order not understandable by investigation of their respective parts in isolation.”
“General System Theory… is a general science of 'wholeness'.”
“Closed and Open Systems: Every living organism is essentially an open system. It maintains itself in a continuous inflow and outflow…”
“Information and Feedback: Another development which is closely connected with system theory is that of… communication.
The general notion in communication theory is that of information. A second central concept of the theory of communication and control is that of feedback.”
“Causality and Teleology: You cannot conceive of a living organism, without taking into account what variously and rather loosely is called adaptiveness, purposiveness, goal-seeking and the like.”
“The System Concept: In dealing with complexes of 'elements', three different kinds of distinction may be made: (1) according to their number; (2) according to their species; (3) according to the relations of elements.”
Other sources say:
“Systems theory is the interdisciplinary study of systems in general, with the goal of elucidating principles that can be applied to all types of systems at all nesting levels in all fields of research.
The term does not yet have a well-established, precise meaning.” Wikipedia
Larry L. Constantine
“Some scholars consider general system theory to be broader than a theory, but rather an alternative Weltanschauung—a unique worldview” (Ruben & Kim, 1975).”
Not everybody accepted that GST is valuable.
The schools of systems thinking have different roots and perspectives; different schools hold sway in different regions.
“General system theory, like other innovative frameworks of thought, passed through phases of ridicule and neglect. (Laszlo and Krippner)
A respectable summary of GST is quoted below:
"von Bertalanffy.emphasized that real systems are open to, and interact with, their environments, and that they can acquire qualitatively new properties through emergence, resulting in continual evolution.
than reducing an entity (e.g. the human body) to the properties of its parts or
elements (e.g. organs or cells), systems theory focuses on the arrangement of
and relations between the parts which connect them into a whole (cf. holism).
This particular organization determines a system, which is independent of the concrete substance of the elements (e.g. particles, cells, transistors, people, etc).
Systems concepts include: system-environment boundary, input, output, process, state, hierarchy, goal-directedness, and information." Principia Cybernetica Web
1956 “General Systems Theory” (von Bertalanffy)
For more, read the first papers under GENERAL SYSTEM THEORY on the "System Theory" page at http://avancier.website.
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