Abstract
In this paper we present how to model data and processes in Colombo, a conceptual framework for Service Oriented Computing where web services are characterized in terms of (i) message exchanges, (ii) data flow, and (iii) effects on the real world. While all these aspects have been separately considered in the literature, dealing with all of them together is particularly challenging: Colombo, by proposing a semantically rich service model for services, enables a single coherent framework, on top of which automatic service interoperability and composition are feasible.