Work Package JRA2 has developed advanced simulation-based methods to check and validateSmart Grid scenarios, configurations and applications. The required models cover the various partsof Smart Grids, such as power system infrastructures, control algorithms, communication systems,market aspects or/and external factors like weather and people. The challenge is that the individualmodels of these parts are of very different nature (continuous, discrete, stochastic, etc.). From thetechnical perspective, this challenge has been overcome with the help of offline co-simulation, wherethe most suitable simulation tools for all considered domain can be coupled via the Functional Mockup Interface specification. From the methodological perspective, this challenge has been addressedby basing the work in JRA2 on ERIGrid’s holistic testing procedure.@en