What do we need to learn about complex systems?
by Philip Boxer
There was a time when organisations could define exactly what it was that they expected from their systems. The job of the designers was then to couple systems’ behaviours that they created and/or inherited in such a way as to over-determine the behaviour of the resultant complex systems and thus satisfy the organisation’s requirements. In judging the actual performance of these complex systems, this same presumption of over-determination allowed the behaviour of these complex systems to be modelled independently of their context-of-use, enabling the risks to be identified of something accidental happening. In the 2 x 2 below, we are in the right-hand column.
But now we want our systems to be agile and responsive, capable of supporting demands on them not previously anticipated. Service-oriented architectures introduce under-determination into the ways systems can be coupled together, while agile software development processes bring the spirit of mash-ups and bricolage to the just-in-time assemblage of workable solutions. (Reducing the way a system over-determines its uses in order to extract greater economies of scope from it is one of the primary aims of SoA, but has the effect of reducing the North-South dominance of those uses).
In the place of a centrally defined requirement, we now find ourselves at the ‘edge’, where the organisation meets the demands on it. Judging performance under these conditions of under-determination now requires us to include the governance mechanisms that are determining those particular responses at the edge.
So how are we to model and simulate such governance mechanisms alongside the behaviour of the systems themselves? The answer is that we have to be able to include the context-of-use itself, which is constituted both by the organisation’s construction of its own role as supplier, and also by the client/customer’s construction of the demand.
What do we need to learn about? We need to learn about how to model the structure-determining processes of the organisation-in-context as well as the structure-determined processes of the systems the organisation uses. We need to learn about modelling the left-hand column.