Towards a quantitative notion of self-organisation

Organic computing (OC) and other research initiatives like autonomic computing or proactive computing have developed the idea of systems that possess life-like properties, that self-organise, that adapt to their dynamically changing environments, and that establish other so-called self-x properties, like self-healing, self-configuration, self-optimisation etc. What we are searching for in OC are not concepts for systems that simply self-organise, but systems that self-organise to achieve a well defined system goal. Therefore we talk in OC about controlled self-organisation. Although the term self-organisation has been discussed for years, we miss a clear definition of self-organisation in most publications, which have a technically motivated background. In this paper, we summarise the state of the art and introduce a definition of self-organisation that addresses the problem of designing self-organising technical systems, which is the main objective of the OC initiative.