When organizations engage in close cooperation they usually need to reorganize the business processes that serve the interface between them. This reorganization is often done with the help of business process models. As a result, the underlying information systems have to be adapted, too. The changes to the latter can be supported by information system models which are typically “written” in a different language from that of the business processes. Here we suggest an approach to facilitate the development of information system models based on the models of the respective business processes. This is achieved by mapping a suitable business process language to the Unified Modeling Language. We apply this approach in the context of an interorganizational business process.