Sustainable health systems should understand information as a resource which also has to be managed efficiently. Today's electronic documentation is only the mandatory first step to automatic information exchange between hospitals, physician offices, pharmacies and other participants. The K-Box is a modular system which allows different monolithic information systems to be connected and integrated by using the clinical document architecture (CDA) as the standard document exchange format. A prototype K-Box has been implemented and a trial run is scheduled. The workflow selected for the trial produces discharge summaries in CDA format.