Process interconnection mechanisms are necessary to co-ordinate geographically distributed business processes in order to strength awareness inside virtual enterprises, to facilitate multinational e-transactions, etc. Actually, existing business process modelling and enactment systems (workflow systems, project management tools, shared agendas, to do lists, etc.) have been mainly developed to suit enterprise internal needs. Thus, most of these systems are not adapted to inter-enterprise co-operation. As we are interested in workflow processes, we aim, through this paper, to provide a model supporting dynamic heterogeneous workflow process interconnection. We consider the interconnection of enterprise workflow processes as the management of a workflow of workflows in which several heterogeneous workflow systems coexist. This paper introduces our process interconnection model, its implementation, and its validation through an experimentation.