Dario Bruneo received his Degree in Computer Engineering from the Engineering Faculty of the University of Palermo (Italy) in 2000 and the PhD in Advanced Technologies for Information Engineering at the University of Messina (Italy) in 2005. Since then he has been engaged in research on distributed systems. He is currently an associate researcher at the Engineering Faculty of the University of Messina. The research activity of Dario Bruneo has been focused on the study of distributed systems with particular regards to the management of advanced service provisioning, to?the?system modeling and performance evaluation. Different research fields have been investigated ranging from the Quality of Service management, to the distributed programming, from ad-hoc and sensor networks to the performance analysis through analytical and simulative techniques. Is coauthor of more than 40 scientific papers on international journals and conference proceedings. Salvatore Distefano is an assistant professor of the Politecnico di Milano. His research interests ?include performance evaluation, parallel?and distributed?computing, software engineering, and reliability techniques. During his research activity, he has contributed in the development of several tools such as WebSPN, ArgoPerformance and GS3.?He has been involved in several national and international research projects. He is author and co-author of more than 80 scientific papers.