Marex bowtie

Major Accident Hazard Risk Assessments (MAHRAs)


An appropriate qualitative major accident hazard risk assessment is an essential component of any Safety Case, and outwith the regimes which require a Safety Case, duty holders may choose to carry out a MAHRA, to identify their own major hazards, the means of reducing the risks there-from and the mitigation of the consequences.

Marex generally use BowTieXP a software programme developed by the Dutch company, Governors. Any effective risk assessment process should identify what is right about what is being assessed as well as what is wrong, and the great strength of this programme is that, when led by an experienced facilitator, the barriers which would prevent the realization of a hazard are identified, as well as the means of mitigation. The result can be the identification of the seriousness of the risk and the means by which the possibility of realization can be reduced. Marex, can also incorporate dedicated Human Factors analysis into the MAHRA process.

The team carrying out the MAHRA is usually made up of the personnel involved in the operation of the unit, so the inputs relate to their direct experience, and any recommendations are pertinent. This make-up fulfills the regulatory requirement that the workforce should be consulted during the development of a Safety Case.

Anyone considering having a risk assessment carried out using a bowtie programme should contact Marex for advice.