  Currently many different modeling languages are used for workflow definitions
in BPM systems. Authors of this paper analyze the two most popular graphical
languages, with highest possibility of wide practical usage - UML Activity
diagrams (AD) and Business Process Modeling Notation (BPMN). The necessary in
practice workflow aspects are briefly discussed, and on this basis a natural AD
profile is proposed, which covers all of them. A functionally equivalent BPMN
subset is also selected. The semantics of both languages in the context of
process execution (namely, mapping to BPEL) is also analyzed in the paper. By
analyzing AD and BPMN metamodels, authors conclude that an exact transformation
from AD to BPMN is not trivial even for the selected subset, though these
languages are considered to be similar. Authors show how this transformation
could be defined in the MOLA transformation language.
