Quantitative Risk Assessment – QRA
A Quantitative Risk Assessment (QRA) is a formal and systematic Risk analysis approach to quantifying the Risks associated with the operation of an engineering process. A Quantitative Risk Assessment is an essential tool to support the understanding of exposure of risk to employees, the environment, company assets and its reputation. A Quantitative Risk Assessment also helps you make cost effective decisions that will go towards ensuring you manage the risks for the entirety of the asset’s lifecycle.
Quantitative Risk Assessment Process
A Quantitative Risk Assessment is when a formal and systematic approach to estimating the likelihood and consequences of hazardous events, and expressing the results quantitatively as risk to people, the environment and your business. Whilst this process is going on, we will make each and every step clear ensuring you have a clear understanding of what we are doing. It also assesses the robustness and validity of quantitative results, by identifying critical assumptions and risk driving elements.
You will need to demonstrate the acceptable risk levels during the approval of any Hazard Plant Construction Plans, or when making significant changes to operations (including plant modification) or manning levels.
Quantitative Risk Assessment studies are typically required for Production and Processing Facilities, High-Pressure Pipelines, and Storage and Importation Sites, including the Liquefied Natural Gas Industry (LNG). They will contribute to an improved decision-making by highlighting many of the accident scenarios that contribute most to the overall risk. Focusing on these will show that you intend to meet what is deemed to be within or more than the standards that are required in your chosen Industry. It demonstrates to your clients that all risks are as low as reasonably practicable (ALARP).
What you get:
- Analysis of potential accident scenarios, including consequences and initiating and controlling factors
- Estimated fatalities (individual, group and societal risk)
- Predicted economic losses
- Predicted environmental impacts
- Risk to specific main safety functions
- Input to operational restrictions and design requirements
- Identification and assessment of preventative and mitigation measures
- Identification of the need for and function/requirements of safety barriers
- Effects of uncertainties and assumptions.
Objectives for a Quantitative Risk Assessment study
- To identify the hazards associated with your facility
- To determine the potential frequencies and consequences of each of the identified hazards
- To determine the system availability of all your protection systems
- To quantify the all the risks associated with a facility (e.g. Risk Contours, Individual Risk Per Annum (IRPA), Potential Loss of Life (PLL) and F-N Plots)
Quantitative Risk Assessment Consultants
A typical Quantitative Risk Assessment study conducted by one of Periculum Global’ range of QRA Consultants consists of the following processes:
Fault Tree Analysis
- A HAZOP study to identify a series of hazardous scenarios that could lead to significant adverse consequences
- A SIL Determination study, typically done using the Layers of Protection Analysis (LOPA) method
- A Fault Tree Analysis (FTA) to determine the event frequencies associated with the hazardous scenarios from the HAZOP and LOPA study
- A consequence analysis to determine the consequences of the hazardous release from a facility
- An Impact Analysis to determine the frequency of a specific hazardous impact using Event Tree Analysis (ETA). ETAs are ‘bottom up’ analytical tree diagrams that determine the overall likelihood of a particular impact following a hazardous release (i.e. Jet Fire, Flash Fire Vapour Cloud Explosion (VCE))
- A Risk Assessment conducted to determine the risks associated with hazardous scenarios
- Risk Reduction Measures to identify the options to reduce or mitigate the risks
- Lifecycle Cost Analysis to provide a Cost Benefit Analysis (CBA) based on different risk mitigation measures