Risk Assessment and LOPA

We specialise in facilitating risk assessments and Layer of Protection Analysis (LOPA) reviews. Risk assessments are important to determine whether the risks posed by your hazards previously identified in the HAZID or HAZOP are tolerable or whether further risk reduction from additional safeguards or controls is necessary. Risk assessments can be carried out using qualitative methods such as risk matrix or bowties, semi-quantitative methods such as LOPA or quantitative methods.

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​QUALITATIVE RISK ASSESSMENT

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Qualitative risk assessments can be carried out using a risk matrix or bowties.

 

The risk matrix method uses qualitative descriptions of consequence and likelihood of initiating events (causes) and effectiveness of controls/safeguards.

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The bowtie method can also be used for qualitative risk assessment. This is a method that represents a hazard with multiple causes and multiple consequence with the top event in the centre of the bowtie which is normally loss of containment of a hazardous substance.

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LOPA

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LOPA is a semi-quantitative risk assessment method that considers the frequency of initiating events (causes) of the hazard and the probability of failure of the safeguards in place (Independent Protection Layers). This then generates an event frequency of the hazardous event that can be compared to tolerable criteria.

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QUANTITATIVE RISK ASSESSMENT

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Fault tree is a quantitative risk assessment method that systematically explores all possible combinations of failures and errors that could lead to a hazardous event. This structured approach helps identify single points of failure, quantify the probability of the hazardous event and prioritize areas for risk reduction.