4. Fourth Lesson: Main Techniques for Risk Modelling

Risk modelling techniques are crucial tools for conducting a QRA. This lesson dives into the commonly used techniques in engineering practice, which facilitate the identification and calculation of risks. By applying these techniques, readers can acquire proficiency to effectively connect theoretical concepts with practical applications in risk analysis. The lesson begins with hazard identification (HAZID) techniques, including HAZOP (Hazard and Operability Study), PHA (Preliminary Hazard Analysis) and FMECA (Failure Modes, Effects and Criticality Analysis). Subsequently, the focus shifts to ​causal, probability and frequency analysis, where techniques like CED (Cause-and-Effect Diagram), FTA (Fault Tree Analysis) and BNs (Bayesian Networks) are explored. For risks influenced by HOFs, the specialized methodologies of BORA (Barrier and Operational Risk Analysis) and Risk_OMT (Risk Modelling: Integration of Organizational, Human and Technical factors) are introduced. With respect to consequence analysis, ETA (Event Tree Analysis), ESD (Event Sequence Diagram) and escalation modelling are presented. Finally, the lesson discusses the principle of online risk analysis, which draws particular focus from regulatory authorities.