"This panel will focus on Dynamic Security Assessment, which is presently one of the main tools to maintain secure operation of electric power systems. In particular, on-line DSA is essential to give advance warning in real time of the proximity to insecure operating conditions. Challenges faced in on-line DSA include running of stability programs in real time, utilizing real-time phasor measurements locally, or in a wide area, and processing of big amounts of data to extract security information. The first presenters will address problems and solutions for simulation-based on-line DSA, including the challenges of parallel processing and new computational algorithms, as well as specific applications. The next ones will focus on measurement and data driven techniques for on-line DSA.?