Simplified Workflow Management with Metadata-Enhanced Petri Nets

Using a Petri net engine to manage workflow processes requires additional interfacing software to connect the Petri net to the real world. Furthermore, changes in the real world or in the process model must often be reflected in the interfacing software, thus creating a potential consistency problem. We present a Petri net-based software architecture in which workflow processes are described as Petri nets, and where the relationships between Petri net parts and real world entities are described as metadata in the Petri net, thereby making the interfacing software generic as well as eliminating the consistency problem. The core element of the architecture is a Petri net engine that allows metadata to be stored in hierarchical colored Petri nets. Another element of the architecture is a generic interface process that queries the Petri net for its contained metadata that describes how to communicate with the real world entities. Finally, the architecture contains a set of communication protocols that are used for the real world communication. As an example we present an application from the printing industry.