Performance Standards

What is a performance standard?

A performance standard is an industry-recognised criterion that defines what a barrier must be capable of doing in order to be considered fit for purpose. Performance standards set the minimum acceptable level of performance for a protective function and are typically defined by the operating company in line with regulatory requirements and industry norms.

Performance standards sit above individual barrier elements in the barrier hierarchy. Where a barrier element represents a specific piece of equipment or procedure, a performance standard represents the broader technical requirement that the element is contributing to. A single performance standard will typically aggregate the status of multiple barrier elements beneath it.

Categories

Performance standards in the BSP are grouped by category, broadly following bow-tie methodology:

• Prevent initiation — controls that prevent a hazardous event from occurring.
• Reduce extent — controls that limit the scale of a hazardous event if it occurs.
• Prevent escalation — controls that prevent a hazardous event from developing into a more severe consequence.
• Emergency preparedness — controls that ensure an effective response if a major event occurs.

From normal operations to major accident

To understand why performance standards are structured the way they are, it helps to think about how a major accident develops. In a well-controlled facility, operations remain within a defined safe operating envelope. A major accident does not typically occur suddenly and without warning, it develops through a series of stages, each representing a further deviation from normal operating conditions.

At each stage of this journey there are controls in place (barriers) designed to halt the progression and return the facility to a safe state. Performance standards represent the requirement for those barriers to be capable of doing their job at each stage. The journey can be understood as follows:

Normal operations: The facility is operating within its defined safe operating envelope. All systems are functioning as required and no deviation is present.

Deviation begins: Something changes, a pressure reading drifts, a piece of equipment develops a fault, a procedure is not followed. The facility is beginning to move outside its normal operating envelope. At this stage the deviation may be minor and recoverable, but if left unaddressed it can develop further.

Hazardous event: The deviation has progressed to the point where a hazardous condition exists — for example, an overpressure situation, a containment breach, or a gas release. The facility is now in a hazardous state, though the consequences have not yet fully materialised.

Escalation: The hazardous event is developing into something more severe. Without intervention, the situation will escalate: a gas release may ignite, a fire may spread, a structural situation may worsen.

Major accident: The situation has escalated to a major accident. The priority is now emergency response: protecting personnel, containing the event, and recovering the facility.

Performance standards exist at every point along this journey. Their purpose is to ensure that the barriers at each stage are capable of doing their job when needed. If a performance standard is impaired, it means that the ability to halt the progression at that stage is reduced making it more likely that a developing situation will advance further along the chain.

In Eigen BSP, Performance standards are grouped into categories that broadly correspond to the stages of the journey from normal operations to major. Each category groups together the standards relevant to a particular stage of that journey. Prevent Initiation, Reduce Extent, Prevent Escalation, Emergency Preparedness. See Performance standard page for more information

How performance standards are scored

The status of each performance standard is calculated by aggregating the status of the barrier elements that contribute to it, using the same scoring rules applied across the rest of the barrier model. An impairment on a contributing element will affect the status of the performance standard above it.

For a full explanation of how scoring works, see Section — Scoring & Colour Coding