This panel session will examine the impact of the node-breaker representation in power flows and transient stability analysis simulation tools on static and dynamic contingency analysis. This panel which includes both software vendors and users will provide a unique perspective from both developers and users. The panel includes participants from North America and Brazil. The panellists will discuss both the analytical issues and results on application to actual systems. The panel will also discuss the ability to directly import real-time data from state estimators.