* Universitat Politècnica de València,
PROS Research Center, Camino de Vera S/N, Valencia, Spain
** Universität Wien,
Research Group Workflow Systems and Technology , Währingerstraße 29, 1090 Wien, Austria
*** University of Twente,
Faculty of EEMCS, Zilverling building Drienerlolaan 5, 7522 NB Enschede, The Netherlands