Understanding human factors in major hazard safety

Human factors have been identified as contributing factors in nearly every major process safety incident. Human factors include staffing and workload, managing human reliability, training and competence, and safety-critical communication.

Why is understanding these factors important?

Being able to identify and address situations where human factors are likely to create a sequence of events that will lead to an incident is one of the most fundamental safety processes we have. To do this effectively, human factors need to be integrated into safety management systems.

People performing normal work continually adapt and overcome unexpected situations, detect changes in risk, are flexible in managing and linking multiple tasks, apply knowledge and judgement to identify patterns and understand impacts of actions, and manage complex communications. Humans manage the normal variability of work. Therefore, human performance plays a significant role in preventing initiation, mitigating the impact, preventing escalation and improving recovery efforts of major incidents or events.

There are limitations to human performance because human reliability is both negatively and positively influenced by performance-shaping factors.

What are performance-shaping factors?

Performance-shaping factors are components that contribute to the likelihood of error or ‘shape’ human performance. Managing human performance involves increasing the likelihood of achieving desired performance outcomes and reducing the likelihood of human failure. We can achieve this by understanding what performance shaping factors are involved. These factors are:

• organisation-related: e.g. leadership commitment, organisational priorities, workplace culture, availability and adequacy of resources, level of supervision, change management, key performance indicators, communication systems • job-related: e.g. difficulty or complexity of tasks, time available, physical work environment, human-machine interface, availability and quality of procedures, team member behaviour, equipment being used • individual-related: e.g. personality, attitude and motivation, mental ability, skills and competence, health factors such as fatigue, drugs and alcohol, physical capability and mental health. Performance-shaping factors are identifiable, assessable and manageable. This means the potential for human failure can be controlled to reduce the risk to as low as reasonably practicable (ALARP) or so far as reasonable practicable (SFARP), and organisational and job conditions can be optimised to improve human performance.

An error tolerant system will have multiple controls (or defences) in place to support human performance and manage human failure. A safety management system that does not identify, assess and control performance-shaping factors may not be sufficient to demonstrate the risks have been reduced to ALARP or SFARP.

New resources

The Department’s Critical Risks team has expanded their capability by bringing a dedicated human factors specialist into their team. Critical Risks is using this expertise in inspections, audits and reviewing safety cases/reports, and upskilling inspectors in this area.

The Department will soon release a guide, Human factors fundamentals for petroleum and major hazard facility operators, along with a human factors self-assessment guide and tool template, to help petroleum and major hazard facility operators to integrate human factors within their safety management systems.