xoEPC - Jan Mendling

96 3. Event-driven Process Chains (EPC)
the state space. Still, certain information about function labels is not present and there is
no direct connection to the process model.
Figure 3.24: Visualization of the Petri
net and the state space in DiaGraphica
Figure 3.25: Clustering of places for the
same state space in DiaGraphica
This shortcoming is the motivation of the work by Verbeek, Pretorius, Van der Aalst,
and Van Wijk [VPAJ07] on a two-dimensional projection of state spaces as an extension
to the Diagraphica tool of Pretorius and Van Wijk [PW05, PW06a]. Diagraphica can
also load FSM files and in addition the diagram of a Petri net. Figure 3.24 shows that
DiaGraphica uses an attribute clustering technique where, in this case, the attributes are
related to the places of the Petri net. As Figure 3.25 shows, there may be multiple places
in a cluster depending on the selections of the user. Transitions are represented as arcs.
This figure permits an interesting observation. Below the diagonal line of yellow clusters
the clustering hierarchy does not branch anymore. This means that for the selected places,
only one can be marked at the same time (cf. [VPAJ07, p.16]). Further interpretations of
different clustering patterns are discussed in [VPAJ07].
Based on the implementation of the reachability graph calculation in ProM, we can
relate the novel EPC semantics to several other tools and approaches for analysis, syn-