ValueTools 2013 is on methodologies and practices in modeling, performance evaluation and optimization of complex systems, gathering researchers from different communities, such as Computer Science, Networks and Telecommunications, Operations Research, Optimization, Control Theory and Manufacturing. ValueTools 2013 solicits previously unpublished contributions on new performance evaluation methodologies and new tools. Three types of contributions are called for: regular papers, tool papers, and tutorials. Submission information for all three types can be found here.