Modeling Self-Expression by Holons

In the field of autonomic computing the current trend is to develop cooperating computational entities enabled with enhanced self-* properties. The term self-* indicates the possibility of an element inside a set (an ensemble) composed of many potentially heterogeneous components to self organize, heal (repair), optimize and configure without little or no human interaction. The goal is to increase the level of adaptivity for both the ensemble and the single element, especially in scenarios in which stopping a system for further tuning is unfeasible. In this paper, we propose an approach to model and enable the capability of adopting different collaboration patterns in ensembles of autonomic components inserted in open and nondeterministic environments. This model takes inspiration from the holonic organisation of multi agent systems and from a Self-* property, called Self-Expression, which is defined as the property of a distributed system to change its collaboration pattern at run time in order to better adapt its execution of tasks in unknown situations. Ensembles able to deploy Self-Expression, show a higher level of adaptation and the concept of Self-Expression can be easily exploited though a Self-Repeating structure like a hierarchy of holons.