Sunday 23 February 2014

Systems Theory - Searching for the Systematic

What's in a name?

Systems Theory has had many incarnations since Bertalanffy's 1968 book on General Systems Theory. Wikipedia has a good summary.

My use of the term is a grossly simplified version of those original ideas. You could say that I am using the paradigm, if not precisely the same incarnation.

My objective is to be pragmatic. To constitute a set of guidelines which can be useful in practice to those of us who have to analyse Systems and those of us who have to design and build Systems.

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I am primarily concerned with Artificial Systems, those built by people for use by people.

Examples of Systems Theory applications
Systems appear throughout the literature on Science and Engineering as a paradigm that is useful in the organisation of ideas. In Science, Systems concepts appear in their analysis form, where scientists seek to systematise their thinking by enumerating (and defining) concepts and their relationships. In Engineering, Systems concepts appear in their synthesis form, where engineers organise the structure of the artifacts they plan to build.

Elsewhere (on the Systems Art website) I have applied the ideas to Art (primarily visual art) in both an analysis and synthesis sense. The reasons that I have done this is that I wanted a domain that was different from the usual domains used in describing Systems Theory. Art is a domain that I know reasonably well and one that I think is accessible to most readers. I hope to make that motivation clear here (and eventually on the Systems Art website). But first let me introduce the basic ideas of Systems Theory.

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Systems Theory, a gentle introduction.

Primarily Systems Theory suggests that we should look at the world through the concept of a System. But of course there are many Systems, so we need to scope our study.

This will involve choosing a Boundary and a Level of Abstraction. Our System will interface with other systems at the boundary. And we will choose a comfortable set of Concepts to work with that together will define the level of abstraction that we are using.

There is no single ideal description of a System. Indeed, it is often important to construct more than one description, to look at the system under consideration from several Viewpoints.

Take an automobile, for example. I can choose to describe that as a system to be designed, to be manufactured or to be used. To take the user's viewpoint, I would describe how to drive and maintain the vehicle. The concepts involved in the description would be those necessary to define the principal functions. These would be at a fairly abstract level, not for example describing how the throttle adjusts the engine speed, just that this is what it does.

For any System, there are two particular viewpoints that complement each other and have general utility. We can describe a System as a Structure, focussing on the components it comprises and their interfaces. Or we can describe a System as a Process, focussing on the behaviour that it exhibits.

In turn, there are two particular process viewpoints that are useful. Sometimes we need one, sometimes the other, sometimes both.

The first process is the behaviour of the systems itself (how the vehicle works). The second process is the behaviour of the system that produced our system of interest (how the vehicle is manufactured). Note the recursion here.

Whether we are analysing or synthesising a system, we encounter the same need to enumerate the concepts suited to our purpose. Either way, we are faced with a puzzle. As System Theorists, we are puzzle-solvers.

What are the components and behaviours we need to identify (then describe, then build or rebuild) and how do they, taken together, constitute a full understanding of the system of interest? This is the universal puzzle that we set ourselves in Systems Theory.

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Systems Theory, an example from Art

When looking at an artifact we can choose to view it as a structure or as the result of a process that might have produced it.

If I can describe something to you in terms of its structure, so that you can understand it without necessarily seeing it, then you will have one view of it.

A statue, for example: I might explain that it is a statue of a man, standing. A Roman man, in Roman attire, from two thousand years ago. He has one hand raised, as if to say something. I can walk all round him and see how how it might have been to be near the real man all those years ago. I can describe the statue to you as a structure.

Or, I can describe something to you by describing the process that might have made it.

That statue: perhaps it had been created by a craftsman, a sculptor. It's marble, not bronze. The sculptor used a chisel and hacked away at just the parts of the marble needed to reveal a Roman senator. The craftsman copied from a small model that had been made by an artist. Two models, in fact. One of the whole man, showing the stance and another more detailed likeness of the face, so that the real senator would be recognizable.

You can call these two descriptions complementary. You can note that they are not the only descriptions. What, for example, was the purpose of the statue? How much did it cost? When was it actually made? Is it a true likeness, or a re-imagined image? Is this a real senator? What did he do to deserve a statue?

You can make many descriptions. The more the better. But structure and process are essential viewpoints. And in searching for the systematic, it is important to use both.

Because, when searching for the systematic, there are many, many systems involved and each will play a part in determining our understanding of the system of interest.