One of the most challenging issues in current e-Government initiatives is the seamless exchange of information and the efficient collaboration between public administrations, companies and the private sector. Either from an intra- or cross-organisational point of view spanning processes across multiple authorities leads to a collaboration of autonomous units under consideration of law and regulations. Despite the organisational dimension current approaches are mainly technical solutions – e.g. interoperability frameworks. Within this paper we present an integrated approach which incorporates organisational aspects of the public sector and which supports the correspondent implementation of solutions for cross-organisational e-Government by adopting Model-Driven-Development practices.