With the regulatory spotlight on operational risk management, there has been ever increasing attention devoted to the quantification of operational risk. The operational risk potential devastating power has been shown by many large operational losses in some of the best known banks and insurance companies across the globe. The objectives of this training program include to: 1. Measure operational risk in financial institutions when historical data are available starting from a fixed threshold; 2. Quantify operational risk applying the Loss Distribution Approach (LDA), a frequency/severity approach widely used in the actuarial models. Risk measures like Value at Risk (VaR) and Expected Shortfall (ES) are used for determining the risk capital necessary to cover the operational risk. The dependence among the events in the operational risk management has been taken into account using copula functions. Extreme Value Theory (EVT) will be used to model the right tail of the severity of loss distributions. The Expectation and Maximization (EM) algorithm will be applied to estimate the parameters of the frequency and severity of loss distributions. The workshop is designed to appeal to very experienced and senior bank risk modelers or analysts who have all the readily obtainable skills and who want to investigate how to quantitatively resolve complex or unusual problems that they are faced with.