“Complex Adaptive Systems”

Copyright 2017 Graham Berrisford. One of about 300 papers at http://avancier.website. Last updated 15/02/2019 14:08

 

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The widespread use of the term “complex system” is questionable.

Some discussion is of disorderly situations rather than systems, but entropy (the absence of order) is reasonably regarded as simple rather than complex.

Some discussion is of unpredictable systems, but we know simple systems can be unpredictable - as per chaos theory.

This paper tries to make sense of the term “complex adaptive system” (CAS).

Contents

Meanings of “complex”, “adaptive” and “system”. 1

The MIT definition of CAS. 2

Conclusions and remarks. 4

Footnote 1: What does “adaptive” mean?. 5

Footnote 2: What does “complex” mean?. 6

 

Meanings of “complex”, “adaptive” and “system

Discussions of systems and definitions of CAS often confuse

·         complexity with unpredictability

·         complexity with disorder

·         system state change with system mutation

·         system with situation.

 

The three terms in CAS mean different things in different schools

 

Term

School

Meaning

Complex

Classical cybernetics

The measurable complication of an abstract system description

Sociological thinking

The un-measurable disorder or unpredictability of a real world situation

Adaptive

Classical cybernetics

System state change – updating the values of system variables

Sociological thinking

System mutation - changing the roles and rules of the system

System

Classical cybernetics

Actors playing roles and acting according to rules

Sociological thinking

A group of elf-aware actors who inter-communicate and act as they choose, or a problematic situation

Emergence

Classical cybernetics

A property arising from coupling subsystems into a large system

Sociological thinking

Not seen before, new.

 

The MIT definition of CAS

MIT offer this definition.

"Complex Adaptive Systems are dynamic systems able to adapt in and evolve with a changing environment.

It is important to realize that there is no separation between a system and its environment in the idea that a system always adapts to a changing environment.

Rather, the concept to be examined is that of a system closely linked with all other related systems making up an ecosystem.

Within such a context, change needs to be seen in terms of co-evolution with all other related systems, rather than as adaptation to a separate and distinct environment."

 

This definition doesn’t tell us what a “system” is, or how to distinguish it from any other kind of entity in the universe.

It uses the term “adaptive” in a way that may be interpreted to mean different things.

And it gives us no hint as to why or how any system, adaptive or not, should be considered “complex”.

 

Let us analyse the definition phrase by phrase.

 

"Complex Adaptive Systems [CAS] are dynamic systems”

The term dynamic may be read as changing or changeable.

Systems are dynamic in the sense they change state in response to external events.

But also, they are dynamic in the very different sense that they can change via generational system mutation.

Isn’t this as true of a simple system as well as a complex one?

 

able to adapt in and evolve with a changing environment.”

The terms adapt and evolve refer to changes inside the system.

A system is connected to its environment by an information feedback loop.

That loop enables the system and its environment (or external actors in it) to change state in step with each other.

But also, in a second and very different sense of change, a system may change via generational system mutation.

Isn’t this as true of a simple system as well as a complex one?

 

System mutation may happen in these three ways.

1.      By self-replication with changes - as a biological system evolves with each new generation.

2.      By redesign by actors outside the system - as a machine or software system is changed in each new version.

3.      By redesign by actors who play roles inside the system - as a human social system may evolve in each new version.

 

Human social systems might evolve in the first two ways above – are those to be ignored?

Probably, the MIT definition is referring to the third kind of mutation.

But is unclear whether MIT mean generational change or continuous change.

If a social group changes continually, it can never be described and tested as a system; so to call it a system is an empty assertion.

 

there is no separation between a system and its environment”

What does no separation mean?

A system is connected to its environment - logically in description, and physically in reality - by an information feedback loop.

But at the same time, you must be able (at least logically) to separate what is inside the system from what is outside.

Else the system has no boundary, and you cannot distinguish it from its environment.

Isn’t this as true of a simple system as well as a complex one?

 

a system always adapts to a changing environment.”

A system adapts by changing state in response to events it detects in its environment.

But in a very different sense of adaptation, a system may evolve via generational system mutation.

Do MIT mean to imply is that the system adapts, rather than the system is adapted?

Do they mean the actors who play roles in the system are the ones who change its roles and rules?

 

the concept to be examined is that of a system closely linked with all other related systems making up an ecosystem.”

The environment outside any one system of interest may be divided into separately describable systems.

And all those systems may be seen as subsystems of a wider system (an eco system if you like).

Isn’t this as true of a simple system as well as a complex one?

 

change needs to be seen in terms of co-evolution with all other related systems, rather than as adaptation to a separate and distinct environment."

In both CAS and classical cybernetics, if one system changes state, then related systems may be triggered to change state.

Or if one system mutates, then related systems may be have to mutate also, if they are to survive.

Isn’t this as true of a simple system as well as a complex one?

 

Another definition of CAS

This from another source introduces the concept of non-linear or chaotic behavior.

“A complex adaptive system exhibits both linear and non-linear behavior.

As per chaos theory, incremental changes to one of its state variables can turn linear quantitative change into qualitative change.

There comes a point where the system behaves in a qualitatively different way.

As per catastrophe theory, the topological shape of the system state space may change dramatically.” Source lost

 

Isn’t this as true of a simple system as well as a complex one?

Chaos appears when turn on a tap, and the stream of water changes from orderly to chaotic.

Conclusions and remarks

Systems thinkers often speak of a social entity or organisation as a CAS.

But in describing a system, we hide the internals of whatever we regard as atomic.

E.g. We may describe an economy in terms of businesses that take money from customers and investors and pay dividends to investors.

At this level of description, IBM is a very simple subsystem.

 

So what does it mean to assert that IBM is a CAS?

Of four possible answers, the last two seem the best.

 

1 IBM as a whole is one very complex system, which is changed frequently under change control.

This is unrealistic; it is impossible to design and maintain such a large and complex system.

And the necessary change control and testing procedures would disable progress.

 

2 IBM changes its organisation/management structure frequently.

This is a poor answer, because it does not necessarily to change what IBM does.

 

3 IBM has a meta system (a strategy and architecture team?) for changing what its actors do.

OK, this meta system is small compared with the countless distinct business systems IBM realises.

 

4 IBM is a complex adaptive social network rather than a system.

OK, it is a society in which the individual human actors are inherently complex and adaptable.

The network of actors employed is large and complex.

They realise many distinct systems, some more flexible than others.

The actors are encouraged to change those systems in response to changes in the environment of – and related systems outside of - IBM.

 

Yes, there is complexity in the intelligence of IBM’s employees.

And there is adaptability in their ability to work with little or no fixed roles and rules.

But that is, in effect, to say IBM is an intelligent flexible entity, rather than a system.

 

In terms of classical cybernetics, Ashby might radically change the terms thus.

·         Complex = Simple - because there is little complexity in the system description, little by way of roles and rules

·         Adaptive = Evolutionary - because any roles and rules we detect now may be changed by the actors

·         System = Unfolding process – because there is no regular and repeatable behavior.

 

How to restore the system concept to systems thinking?

Read Social networks versus social systems for an answer to that question.

 

How to extend system theory to embrace “self-organisation”?

Read System stability and change for an answer to that question.

Footnote 1: What does “adaptive” mean?

How to measure adaptiveness?

Which is more adaptive out of IBM, Microsoft and Apple? Or out of IBM and a chicken?

 

The use of the term “adaptive” is questionable.

Some discussion is of system state change; some is of system mutation.

 

 

Changes

For example

System state change

the value of at least one state variable

homeostatic regulation of values to stay within a desired range

System mutation

the type of at least one variable or behavior.

re-organization changing the variables or the rules that update their values.

.

System thinkers often use the term adaptive in one or other sense of self-organising.

 

Self-organising systems

Again, systems thinkers speak of self-organising systems, but with two very different meanings.

 

-1- A system that settles into one or more stable states: for example, a solar system, a weather system, an organism.

Here, “self-organisation” does not change the laws of the system, it an inexorable mathematical result of those laws.

It is the basis of homestasis in biological and technological “machines” and classical cybernetics.

 

-2- An entity or social network that realises several systems over time; for example, IBM.

Here, “self-organisation” means changing the very nature of the system; changing its laws.

It is the basis of second-order cybernetics (very different from classical kind).

 

Second-order cybernetics

This was developed around 1970 by Margaret Mead, Heinz von Foerster and others.

It is the recursive application of cybernetics to itself.

It allows systems actors to be system thinkers, who re-organise themselves.

It allows actors in a system to study the system and change it.

Actors not only play roles in a system, but also observe and change the roles, rules and state variables of that system.

 

You can’t play a game of tennis unless all players agree the rules, at least for the duration of each rally/point.

Provided actors change a system incrementally, the classical concept of a system is upheld.

But if actors change a system continually, this undermines the very concept of a system.

It is disorganising rather than self-organising.

Footnote 2: What does “complex” mean?

The use of the term “complex system” is questionable.

Some discussion is of disorderly situations rather than systems, but entropy (the absence of order) is reasonably regarded as simple rather than complex.

Some discussion is of unpredictable systems, but we know simple systems can be unpredictable - as per chaos theory.

 

How to measure complexity?

Which is more complex out of IBM, Microsoft or Apple? Or IBM and a hen’s egg?

 

Complexit science?

A commonly-referred-to chart of “complexity science” can be found here http://www.art-sciencefactory.com/complexity-map_feb09.html

The chart is misleading chronologically and conceptually.

Conceptually, the chart mixes up science, pseudo science and metaphysics.

It mixes up scientists with people who make assertions and classify things with no empirical validation.

It includes people (e.g. Parsons and Luhmann) whose ideas are metaphysical – cannot be verified or disproved.

And note one misleading implication: the line from first to second order cybernetics suggests a progression rather than a schismatic difference.

 

Chas theory?

Does complex mean unpredictable or chaotic behavior?

By complex, people often mean a system has non-linear dynamics, or changes the state of world in a chaotic fashion.

But the equation is misleading.

 

The Plexus Institute glossary at https://plexusinstitute.org/ says:

"complexity is found in systems when there are unpredictable interactions of multiple participants and components across many levels of the system."

The glossary contains no definition of "system", or what the "levels" of a system are.

It appears to equate complexity and unpredictability, yet these are different qualities.

A complex system can behave in a linear or predictable way over time.

A simple system can behave in a non-linear of chaotic way over time.

Chaos theory taught us even the simplest of orderly systems can be unpredictable can produce chaotic results over time.

And one system’s behavior may switch from linear to non-linear change, and back again.

 

Complex or complicated?

Some systems thinkers use the terms complex and complicated as though the latter is simpler.

Mostly, it seems, they are really contrasting realities and descriptions.

They are contrasting concrete realities (complex) with abstract descriptions (merely complicated).

Or contrasting a human’s behavior in the world (complex) with their behavior acting in a defined role (merely complicated).

 

 

Social

Business

“Complicated” abstract system

Exchanging Birthday cards

Order > Invoice > Payment

“Complex” concrete system

A network of friends

IBM finance department

 

How measure complexity (or complication)?

There seems no agreed way.

One thing is certain, to measure the complexity of a thing, you need a description of its parts.

And to compare the complexity of two things, those parts must be described comparably, at the same level of abstraction.

 

At the topmost level of description, the organisation structure of IBM is simple.

By contrast, a description of IBM that included every human actor in it would be exceedingly complex.

But then, a description of a hen’s egg that included every atomic particle would be even more complex.

 

Often, an entity is called a CAS where one or more of the following are true.

·         No measure of complexity has been agreed

·         No level of abstraction has been agreed

·         No quantifiable properties are described, which makes any measure of complexity impossible.

·         No description of the entity as a system has been agreed, or even made.

·         No description is possible, because the entity changes continually, rather than generationally.

 

Some naively presume that the complexity of an organisation lies in its management structure.

Or (after Ashby and Beer) a system’s complexity is defined by the number of variables it maintains.

Our paper on complexity measures points out that one ought to measure the complexity of behaviors as well as structures.

 

 

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