Risk modellingRisk modelling techniques are crucial tools for conducting a QRAQuantitative Risk Assessment (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 analysisRisk analysis. The lesson begins with hazard identification (HAZID)Hazard Identification (HAZID) techniques, including HAZOPHAZOP (Hazard and Operability Study), PHA (Preliminary Hazard Analysis)Hazard Analysis (HAZAN) and FMECAFailure Modes, Effects, and Criticality Analysis (FMECA) (Failure Modes, Effects and Criticality Analysis). Subsequently, the focus shifts to ​causal, probability and frequency analysis, where techniques likeCause-and-Effect Diagram (CED) CED (Cause-and-Effect Diagram), FTAFault Tree Analysis(FTA) (Fault Tree Analysis) and BNs (Bayesian Networks)Bayesian Networks (BNs) are explored. For risks influenced by HOFsHuman and Organizational Factors (HOFs), the specialized methodologies ofBarrier and Operational Risk Analysis (BORA) BORA (Barrier and Operational Risk Analysis) and Risk_OMTRisk_OMT (Risk ModellingRisk modelling: Integration of Organizational, Human and Technical factors) are introduced. With respect to consequence analysisConsequence analysis, ETAEvent Tree Analysis (ETA) (Event Tree Analysis), ESDEvent Sequence Diagram (ESD) (Event Sequence Diagram) and escalationEscalation modelling are presented. Finally, the lesson discusses the principle of online risk analysisRisk analysis, which draws particular focus from regulatory authorities.