Modelization of a communication protocol for CSCW systems using coloured Petri nets

Concurrency management protocols are implemented over collaborative platforms in order to manage the shared object modifications. We have defined the Chameleon protocol which allows us to obtain a dynamic management of collaborative architecture. Now, we want to use this algorthm over a telemedicine platform within a European project on tele-diagnosis for neurology: TeNeCi. In such a domain, a robust (no errors, no losses...) management of interactions between cooperative members is crucial; Indeed, TeNeCi must provide an efficient and infallible tool to doctors in order to establish a collaborative diagnosis. So, we must validate and prove the Chameleon robustness. Coloured Petri Nets allowed us to correct the Chameleon weaknesses we have discovered during this modeling. Indeed, a time-out and an automatic forwarding mechanisms have been implemented in the first version of our communication protocol. In addition, a timestamp has been added to some messages sent to inactive sites. Finally, a lock mechanism during a particular step has been also implemented in the Chameleon. Due to those results, we have proved that our protocol is robust. Thus, it can be used in medicine applications.