From task descriptions via colored Petri Nets towards an implementation of a new electronic patient record workflow system

We consider a given specification of functional requirements for a new electronic patient record system for Fyn County, Denmark. The requirements are expressed as task descriptions, which are informal descriptions of work processes to be supported. We describe how these task descriptions are used as a basis to construct two executable models in the formal modeling language Colored Petri Nets (CPNs). The first CPN model is used as an execution engine for a graphical animation, which constitutes a so-called Executable Use Case (EUC). The EUC is a prototype-like representation of the task descriptions that can help to validate and elicit requirements. The second CPN model is a Colored Workflow Net (CWN). The CWN is derived from the EUC. Together, the EUC and the CWN are used to close the gap between the given requirements specification and the realization of these requirements with the help of an IT system. We demonstrate how the CWN can be translated into the YAWL workflow language, thus resulting in an operational IT system