Abstract
We present a formal model for agent-oriented Virtual Organisations (VOs) for service grids and we study an associated operational model for the creation of VOs. The model is intended to be used for describing different service grid applications based on multiple agents and, as a result, it abstracts away from any realisation choices of service grid applications, the agents involved to support the applications and their interactions. Within the proposed framework VOs are created within societies of agents, where agents are abstractly characterised by goals and roles they can play within VOs. In turn, VOs are abstractly characterised by the agents participating in them with specific roles, as well as the workflow of services and corresponding contracts suitable for achieving the goals of the participating agents. We illustrate the proposed framework with an earth observation scenario, we discuss implementation issues, and we compare our approach with existing work.