Quantitative Risk Analysis
The main steps of a Quantitative Risk Analysis are shown in the Figure below:
Figure: Main Steps in a QRA (
Ref. NORSOK Z-013).
The QRA starts with a Planning and System Definition phase during which the analysts systematically work through the available project documentation in order to obtain an understanding of the design and operation of the installation. The boundary for the analysis is defined in this phase.
Based on regulations laid out by safety authorities as well as company specific requirements, Risk Acceptance Criteria for the installation are established.
A systematic Hazard Identification are performed in order to identify the potential hazardous events that will be further addressed in the QRA.
In the Frequency Analysis, the probabilities of occurrence for the identified hazardous events are evaluated based on statistical data and installation specific data. Read more
The Consequence Analysis involves modelling the effects of the accidental events. Advanced tools like Kameloeon Fireex, FLACS, OLGA2000 as well as more simplified tools may be used. Read more
The Risk Picture is estimated by use of probabilistic models combining the frequency and consequence analyses.
The risk picture is compared to the established risk acceptance criteria, and Risk Reducing Measures are identified according to the ALARP principle.