Explore how Equinor handles uncertainty in reservoir planning through this 40-minute conference talk. Dive into ensemble-based methods and the process of optimizing and updating uncertain models. Learn about variants of the Kalman Filter algorithm for model ensembles and efficient gradient approximation techniques. Discover practical applications in reservoir planning, windmill farm design, and beyond. Gain insights into Equinor's open-source project ERT (Ensemble Reservoir Tool) and its use in the industry. No prior knowledge required for this accessible introduction to dealing with uncertainty in engineering decision-making.