Conduct Effective Quantitative Risk Assessment (QRA) Studies

Quantified Risk Assessment (QRA) can be used for a number of different purposes. However, it is most valuable as part of a Risk Management program. Risk Management is the identification and control of hazards, through both technological and management solutions. Occasionally QRA is conducted solely to meet a regulatory requirement, but this rarely precludes using the results as part of a corporate risk management program.

QRA can be used to estimate the absolute level of risk of an activity or the comparative risks of alternatives. The results of absolute risk assessments can be compared with predetermined risk tolerability standards. Comparative risk studies are used to help select, or eliminate particular options. Risk takes many forms; injury to employees and third parties, environmental damage, capital losses, business interruption costs, compliance, and fines. QRA can address any and all of these, so it is important to decide which risks are to be included in each study.

Generally, companies define a level of risk that is considered intolerable. In a few countries, such as in the United Kingdom, regulations include definitions of intolerable levels of risk. More commonly, internal stan- dards of tolerability are set based on the incident related costs an organization can bear each year, as well as levels of risk that society, and investors in particular, will tolerate.

Even when the tolerability standard is met, additional risk reduction measures may be justified if the benefits outweigh the costs. QRA often includes cost/benefit analysis of all or selected risk reduction alternatives. In these cases internal investment criteria may be applied to select measures for implementation.

Usually a wide range of options to reduce risk is available. But it takes skill to select the most cost-effective alternative. Is it better to go after a multitude of easily implemented modifications, or a few more expensive options?

You must also consider what to include in the overall risk. Manufacturing sites generally pose risks only to the work force and the surrounding community. If risks are to be considered for single units, it must be recog- nized that the unit may represent only part of the overall risk. Whole divisions or product lines may put a more diverse and ill-defined group at risk. Since a company may have facilities throughout the world, the overall risk from all of these facilities and all product lines may influence risk tolerability standards.

Before a QRA is conducted, the purpose of the study must be determined so that the appropriate results are generated. The facilities and risks to be included must also be determined. Any special reporting needs, such as regulatory requirements or local language, should be identified. Finally, QRA methodologies that will pro- vide the required results must be chosen. All of these decisions require management processes and policies to guide the individuals responsible for overseeing and conducting the QRA.

ioMosaic considers that QRA consists of two principal steps; preparation – where the objectives, scope, standards and methodologies are selected; and implementation. Without adequate preparation, it is unlikely that the QRA will meet the needs of the end customer.

Computerized Tools

The ioMosaic engineer will record the Hazard Identification findings of the team in Process Safety Office™ PHAGlobal® software. PHAGlobal® templates are designed to document the findings of all types of hazard identification approaches including HAZOP, What-IF, and FMEA. Copies of the findings are distributed to every member of the team for review and comment daily during the hazard identification study. Once the study is complete, the findings are collated for review and comments incorporated.

ioMosaic uses Process Safety Office™ SuperChems™ software to estimate the overall risk. After data is input it is then combined by SuperChems™ to provide an estimate of the overall risk. The results are generated in the format selected during the preparation phase. At this stage a sensitivity analysis may be required to better understand the key contributors to the overall risk. Such an analysis allows us to make sure that any critical assumptions are reviewed carefully and to identify the most effective risk mitigation strategies.

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