Business processes play a central role in the reorganization of a company and the (re)design of the respective information system(s). Typically the processes are described with the help of a semiformal, graphical language such as the Event-driven Process Chains (EPCs) by Scheer. This approach provides a suitable medium for the communication between the participants: the domain experts and the IT specialists. But these models leave room for interpretation and hence ambiguities which makes them less suitable as a basis for the design of information systems. To remedy this we suggest to transform the EPCs into a formal representation (Petri nets) preserving the ambiguities, i.e. all possibly intended behaviour. Now formal techniques can be used to find out whether the possible behaviours comprise sensible behaviour. If so, we call the net relaxed sound. By not limiting the modeler compared to previous ways (e.g. [8], [3]) we take a pragmatic approach to correctness which only requires tha...