Best Practice for Risk Based Inspection

6. RISK ANALYSIS PROCEDURES
6.1. ELEMENTS OF THE PROCESS
Risk based inspection requires the Duty Holder to undertake a risk analysis for the
systems and equipment under consideration. The form of this analysis can vary
considerably, depending on circumstances, ranging from descriptive qualitative
approaches to numerical quantitative approaches. In all approaches, however, the
risk analysis should contain the following stages:
• Identification of accident scenarios involving failure of the equipment
• Identification of potential deterioration mechanisms and modes of failure
• Assessment of the probability of failure from each mechanism/mode
• Assessment of the consequences resulting from equipment failure
• Determination of the risks from equipment failure
• Risk ranking and categorisation
Whatever approach is adopted, the risk analysis needs to be complete, systematic
and thorough. Duty Holders should ask themselves:
• Have all the stages been addressed for all the equipment under consideration?
• Has a uniform approach been applied throughout the analysis of all items?
• Have all the accident scenarios been identified and analysed in sufficient detail?
Risk analysis may be applied at different levels of detail. Some industrial risk
analyses, such as those for complex chemical plant, are sometimes very
sophisticated and consider a wide range of accident scenarios resulting from many
different initiating events. In risk analyses of simple systems, such as industrial
boilers, the range of hazards and consequences is more limited and easier to
identify.
It is the legal duty of every employer to perform an assessment of the Health and
Safety risks arising as a result of their undertaking. The relevant requirement is in
the Management of Health and Safety at Work Regulations 1992, Regulation 3(1)
(6.1). ‘Every employer shall make a suitable and sufficient assessment of:
(a) The risks to the Health and Safety of his employees to which they are exposed at
work; and
(b) The risks to the Health and Safety of persons not in his employment arising out
of, or in connection with, the conduct by him of his undertaking’.
Employers and individuals with pressure systems and hazardous materials at their
premises should, therefore, have a risk analysis as part of the risk assessment
required under the Health and Safety at Work Regulations.
Risk based inspection requires a particular form of risk analysis. This should focus
on the dangers of equipment failure resulting from deterioration that could be
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