Simulations require detailed equipment models -often provided by manufacturers -coupled with detailed interconnection between equipment units, and process data like pressures, temperatures, flow rates, etc. Little of this data is available publicly, as site designs are proprietary information. These simulators are used to investigate failure conditions, by creating failure conditions and observing resulting emissions, safety issues, 245 etc. Each simulation lasts a few minutes and produces highly detailed results. However, simulations are too computationally intensive to simulate the long durations needed to characterize the frequency and duration of failure events.