SIEGE (Software Innovation for E-Government Expansion) is an ongoing research project, co-funded by the Italian Ministry for Scientific Research. SIEGE is being carried out by Engineering, the leading Italian IT company, in partnership with DIIMA, the department for informatics and applied mathematics of Salerno University. As its name suggests, SIEGE deals with software innovation in the field of e-Government. It is being focused on research topics widely recognized by the e-Government research community as relevant to bring efficiency and innovation in public service delivery: interoperability, workflow management system, GRID and semantics. In this paper we describe our effort to accommodate them into a coherent architectural model. Believing that the sharing of "resources" will be paramount in supporting delivery of innovative, and cost efficient e-Government services, we chose an OGSA based architecture. © 2008 Springer Berlin Heidelberg.