System analysis and modeling : 4th International SDL and MSC Workshop SAM 2004 Ottawa Canada June 1 4 2004 ; revised selected papers This book constitutes the thoroughly refereed postproceedings of the 4th International Workshop on SDL and MSC SAM 2004 held in Ottawa Canada in June 2004. The 19 revised full papers presented were carefully selected during two rounds of reviewing and revision from initially 46 submissions. The papers are organized in topical sections on SDL and eODL evolution of languages requirements and MSC security SDL and modeling and experience