ISSUE 176 : Jul/Aug - 2008 - Australian Defence Force Journal

CAS thinking is central to two modern military concepts closely connected to C2: Network
Centric Warfare (NCW) and Effects-Based Operations (EBO). Both of these involve systems
and systems-of-systems that have the building blocks and properties of CAS. NCW relies on
understanding how the increased flow of information between different components within a
force can improve effectiveness. At the heart of EBO is the requirement to understand yourself,
the adversaries, and other players as interacting systems and devise the most useful actions
to produce the desired outcomes. Thus, for the ADF to make these concepts operational and
useful for C2, an understanding and application of CAS thinking is important.
What are the relevant CAS concepts?
The current understanding of CAS identifies a number of concepts and issues of interest to
future C2. While some of these could be deduced from other disciplines—such as strategic
thinking, management science, organisational behaviour and military analysis—these
commonalities simply emphasise the applicability of the study of CAS to military affairs.
Perhaps the most basic description of a CAS is that it consists of a number of heterogeneous
entities and relationships that dynamically interact. One key feature of these relationships is
that they are nonlinear, that is, a given input may produce anything from a disproportionately
large effect to no effect at all and this may change over time. 5 Another feature is that many
of these relationships combine to form feedback loops, which means that a single cause will
produce effects that propagate and return to impact the original causation in some way.
Holland defines a framework that outlines seven key properties and/or mechanisms of complex
adaptive systems as part of his work on genetic algorithms (Holland 1995): aggregation, building
blocks, diversity, nonlinearity, tagging, flows and internal models. This means of characterising
CAS has been particularly useful for computer simulation of evolutionary systems. Axelrod and
Cohen extend on the themes of Holland with a focus on organisational systems as complex
adaptive systems. They are particularly concerned with three key processes in CAS—variation,
interaction and selection—which they regard as ‘interlocking sets of concepts that can generate
productive actions in a world that cannot be fully understood’ (Axelrod & Cohen 1999).
What we are interested in are the resultant features of CAS that practitioners must deal
with: the effects of complexity—essentially the phenomenology—rather than the underlying
mechanisms that may produce them. This is not a better view, simply a different view focused
upon behaviours of principal concern to the practitioner. We are interested in articulating
and discussing what the military commander actually sees and providing a lens with which
to comprehend it.
Characteristic features of complex systems
We argue that there are three key phenomena of complex systems: continual Change, persistent
Patterns and irreducible Uncertainty. These concepts are, to a degree, interrelated, but they
are treated distinctly for the purposes of clarity.
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