Human Factors in the Process Industries: Managing Safety-Critical Tasks

The Role of Human Factors in Major Accident Hazards

Human performance is a decisive element in the safety of oil, gas, chemical, and other high-hazard industries. Analyses show that human failures contribute to the majority of industrial accidents. For instance, nearly 40% of upstream oil and gas incidents have been attributed to human factors. Major disasters such as Piper Alpha and BP Texas City were initiated by human errors or omissions, underscoring that technical safeguards alone are not enough.

Human factors refers to the environmental, organizational, job, and individual characteristics that influence behaviour at work and can affect health and safety. Recognising this, regulators (e.g. the UK’s COMAH regime) mandate robust human factors programs to manage risk as rigorously as engineering measures.

Common Types of Human Error and Their Causes

Human errors can be classified into:

• Slips and lapses – unintended errors in routine tasks, such as pressing the wrong button or forgetting a step.
• Mistakes – errors in decision-making due to knowledge gaps or incorrect assumptions.
• Violations – deliberate deviations from procedures, often due to time pressure or impractical rules.

Underlying causes include poor equipment design, high workload, fatigue, distractions, and weak communication systems. Addressing these performance-influencing factors is key to reducing human error.

Case Studies: Major Accidents and Human Error

Piper Alpha (1988)

A maintenance crew left a relief valve removed and inadequately tagged during a shift change. The night crew, unaware, started a pump, causing a massive gas leak and explosion. A flawed permit-to-work system and poor communication were central to the tragedy.

BP Texas City (2005)

Operators deviated from startup procedures, overfilling a distillation tower, leading to an explosion. Investigators cited a poor safety culture, inadequate training, and normalized procedural deviations as underlying causes.

Best Practices for Managing Safety-Critical Tasks

1. Training & Competence – Ensure operators are well-trained, competent in emergency response, and aware of why procedures matter.
2. Clear Procedures – Develop user-friendly procedures and checklists for safety-critical tasks.
3. Human Reliability Analysis (HRA) – Identify and mitigate error-prone steps through structured task analysis.
4. Just Culture – Encourage reporting of near-misses without fear, fostering proactive safety improvements.

The Role of Automation in Reducing Human Error

Automation and technology can enhance reliability by:

• Reducing cognitive load on operators through intuitive control systems.
• Automating routine process adjustments and safety shutdowns.
• Deploying robotics for hazardous tasks (e.g., offshore inspections).

However, poor automation design can introduce new risks, such as complacency or inability to intervene effectively. A balanced approach ensures that automation complements human decision-making rather than replacing it entirely.

Conclusion

Human factors play a crucial role in process safety. By designing systems that support human reliability—through training, procedures, error analysis, and smart automation—industries can significantly reduce the risk of catastrophic accidents.