Introduction to general system theory

von Bertalanffy’s ideas

Copyright 2017 Graham Berrisford. One of about 300 papers at http://avancier.website. Last updated 23/02/2018 12:03

 

 

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.

The following papers add many more system theory terms and concepts.

Contents

The general idea. 1

Holism.. 2

System nesting. 3

Homeostatic v progressive systems. 3

Information flows. 4

More questionable ideas. 4

References. 7

 

The general idea

The primacy of behavior

To some, the term "system" means no more than "an entity that contains things interrelated in some way or another".

This definition applies to passive structures, like a garden fence, a telephone directory, a necklace, or the Dewey Decimal System.

However, most general system theorists use the term in a richer, more demonstrably useful way.

They focus on activity systems in which structures/parts interact in behaviors/processes.

 

General system theory focuses on the behaviors of activity systems rather than their structures.

 “The principal heuristic innovation of the systems approach is what may be called ‘reduction to dynamics’ as contrasted with ‘reduction to components’ ” Laszlo and Krippner.

 

To some, the term "system" means no more than "an entity that contains things interrelated in some way or another".

This definition applies to passive structures, like a garden fence, a telephone directory, a necklace, the Dewey Decimal System, or a data structure.

However, most general system theorists use the term in a richer, more demonstrably useful way.

They focus on activity systems in which structures/parts interact in behaviors/processes.

Bertalanffy: general system theory

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

Holism

Bertalanffy used the term "system" to mean an entity in which the parts behave holistically.

His interest was in how parts interact and cooperate to enable the whole, or serve the whole.

“General System Theory… is a general science of wholeness… systems [are] not understandable by investigation of their respective parts in isolation.” Bertalanffy

 

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.

 

Emergent property: a behaviour 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.

Typically, the property is not found in any one part, or predictable by studying a part in isolation from others.

The exception is systems with homogenous populations, where a subset of the whole may have the same properties as the whole.

(Note that emergent properties are the very purpose of system design.)

 

Atomic element: a part that is not further divided in a description of a system.

Describers decompose a system to the level they regard as atomic elements.

E.g. An organ in the human body, a human in a society, a note in a musical score.

Or any one-person-one-place-one time activity in a human activity system                                     

Atomic system actors may be complex entities in their own right, and may play roles in other systems.

 

This system

has atomic actors

that perform behaviors

The solar system

sun and planets

orbits

An email system

computers

executable instructions in source code

A human activity system

humans

steps in work procedures

A beehive

bees

deliver pollen, perform and observe wiggle dances

A predator-prey system

wolves and sheep

eat sheep, eat grass

The global ecology

animals and plants

transform oxygen into carbon dioxide, and vice-versa

 

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.

System nesting

Bertalanffy wrote of a concept he called organicism.

 

Organicism: the idea that systems are describable at multiple hierarchical levels

E.g. Consider the decomposition of a human body through organ, cell and organelle to molecule.

Or the decomposition of software application through component, class and operation to executable instruction.

 

As a biologist, von Bertalanffy was thinking of organic, highly evolved entities, like a plant or animal.

He meant not only that larger systems can be decomposed into smaller ones, and vice-versa.

But also, that a system depends on integration and cooperation between its subsystems.

An animal’s organs are composed from cells that interact in processes to sustain the organ.

The cells are composed from organelles that interact to sustain the cell.

The organelles are composed from organic molecules that interact to sustain the organelle.

 

You might think also of a designed, electro-mechanical entity like a radio or a car.

E.g. an automobile may be decomposed into chassis, wheels, steering, and engine, block, cylinder, valve.

However, a motor car does not depend on interaction and cooperation between its engine and its radio.

And some now use the term of system of systems much more loosely, to mean merely a container of systems.

 

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:

·         Systems can be hierarchically nested: one system can be a subsystem of another (and can overlap with another).

·         An event that is external to a smaller system is internal to a larger system

·         The emergent properties of a small system are ordinary properties of any larger system it is a part of.

Homeostatic v progressive systems

Early system theorists were especially interested in self-regulating systems such as the physiological systems of the body.

A homeostatic system (natural or designed) maintains itself in a stable or viable state through input/output feedback loops.

 

Bertalanffy considered a biological entity as a thermodynamic system in which homeostasis maintains order and keeps entropy at bay.

“By importing complex molecules high in free energy, an organism can maintain its state, avoid increasing entropy…."

 

Homeostatic behaviours (maintaining a system’s state variables in a desirable range) may run cyclically or continually.

By contrast, end-to-end behaviors run from start to end, yielding a result or output.

In business systems, these behaviors are usually called value streams, scenarios or processes.

The trigger that starts an activity (or sometimes the activity itself) is often called an event.

Information flows

Bertalanffy related system theory to communication of information between the parts of a system and across its boundary.

connected with system theory is… communication. The general notion in communication theory is that of information.” Bertalanffy

 

The idea that a system is bounded leads to other ideas.

“Systems concepts include: system-environment boundary, input, output, process, state….”   Principia Cybernetica

 

System environment: the world outside the system of interest.

System boundary: a line (physical or logical) that separates a system from its environment

System interface: a description of inputs and outputs that cross the system boundary.

System state: the current structure or variables of a system, which may change over time.

 

These notions are central to cybernetics.

The trigger that starts an activity (or sometimes the activity itself) is often called an event.

We usually describe or model a system as what is called a discrete event-driven system (DEDS).

System architects do this whenever they use system modelling languages like UML, ArchiMate or BPMN.

More questionable ideas

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?

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.

 

Complex?

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.

 

Inexorable progress?

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.

 

Goal directedness?

Any observer can ascribe goals to a system – be it designed or natural – be it a cuckoo clock, a choir or a beehive.

Different observers can ascribe different goals; and different stakeholders have different concerns.

Obviously, systems are designed with goals in mind – prioritising the goals of system sponsors and owners.

 

Classical system theory presumes the individual actors in a system perform actions in accord with the goals of the roles they play.

By contrast, social systems thinkers interpret goal-directedness as meaning that individual actors have their own goals.

Ackoff spoke of human institutions or organisations as “purposeful systems”, meaning each actor as their own purposes.

 

Classify does not identify individual actors, so can say nothing about any goals individual actors have - outside their roles in a system.

The goals of individual actors may have to be addressed by business managers and a business change or HR team in parallel with enterprise architecture.

Read Goal-directedness for more.

 

What more of von Bertalanffy?

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

“Systems theorists seek to explain the behavior of complex, organized systems from thermostats to missile guidance computers, from amoebas to families.” “Systems Theory” Gail G. Whitchurch, 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.

Rather 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

References

1956 “General Systems Theory” (von Bertalanffy)

 

 

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