Most of the efforts conducted on e-Government services nowadays are focusing on data workflow processes within and between PAs, often disregarding the fact that, from the citizen's perspective, what counts most is the performance of the global process involving people and organizations as well as software artefacts. Our main claim is that it is necessary to include this social dimension in reference models for e-Government services for many reasons, ranging from semantic interoperability to transparency issues. Along these lines, we sketch a preliminary definition of "service" based on an ontological analysis centred on the notion of service availability, which results in useful distinctions between service, service content, service delivery and service process. Services are modelled by means of a layered set of interrelated events, with their own participants as well as temporal and spatial locations.
