A performance standard includes the overall measures of suitability and efficiency of the safety systems/-functions to carry out their designated role. Performance standards should ensure that the barrier (safety system or safety function):
- Is suitable and fully effective for the type or has adequate resistance to any preceding hazard
- Has sufficient capacity for the duration of the hazard or the required duration of operation/survival of the system. For example, a system may be required to keep functioning until evacuation has been completed.
- Has sufficient availability to match the frequency of the initiating event and the acceptability criteria for escalation to a major accident or critical failure. This should determine whether or not backup systems or contingency measures are needed to cover for maintenance and breakdown.
- Has adequate response time to fulfil its role.
- Is suitable for the environmental conditions within the maintenance and repair constraints of the operation and maintenance philosophy.
- Is suitable for typical operating conditions (impact, abuse etc.).
- Is operable by the quality of the personnel available on the platform under realistic incident conditions. This could include initiation and/or isolation and reinstatement of damaged systems, e.g. ring mains.
- Can be maintained under actual environmental and manning limitations and thus ensure the availability requirements are met.