Web Services Orchestrations require a firm mathematical basis for their
development. We start from the ORC formalism proposed by J. Misra and
co-workers, at Austin University. ORC is small and elegant and
captures the essence of Orchestrations. We translate ORC into
colored Petri net systems, a generalization of Petri nets allowing to
handle recursion -- this formalism was recently proposed by Devillers
et al. Our approach applies as well to standards such as BPEL.
This work is partially supported by RNRT (National Research Network in Telecommunication) through the SWAN project (Self aWare mANagement).