Dynamic Risk Assessment: A Tool for Process Safety Assessment and Management

Dynamic failure assessment is a new approach in process safety management, which enables the real time failure analysis of a process. Dynamic failure assessment has been used in the past by nuclear industries for accident likelihood estimation using accident precursors. Recently it has been successfully applied to process units to revise failure probabilities using incident and near miss data. In dynamic risk assessment, an extension of dynamic failure assessment, Bayesian and joint probability theories are used to develop a predictive failure model for a given process. As the process operates and generates incidents and near misses, the accident occurrence probability is predicted using accident precursors and later multiplied with consequences to quantify real time risk.The concept of developing a dynamic risk profile for a process system which encompasses likelihood and consequences of a given abnormal event is presented here. Dynamic risk estimation uses Bayesian theory to update the likelihood of an event occurrence and a generalized consequence algorithm to obtain the relative consequences of the given event. This approach results in a risk function which has predictive capabilities and the ability to be updated with time; it is ideal for accident prevention and dynamic decision making. Different real life applications of the dynamic risk assessment is also presented.