Human Factors Safety Critical Task Analysis

SI Group appointed us to update their Human Factors Safety Critical Task Analysis procedure to ensure it was efficient and consistent, and to undertake a Safety Critical Task Analysis assessment.

Challenge

SI Group identified an opportunity to streamline their approach to identify and assess their Safety Critical Tasks (SCTs). This would improve their understanding of where the operator plays an important role in maintaining safety and to help ensure their operational risks are as low as reasonably practicable. They had developed their own Human Factors SCT Analysis procedure but appointed us to update it and ensure the procedure was applied appropriately and consistently.

After successfully implementing the guidance to review plant Major Accident Hazards (MAH) identified from their hazard identification processes, SI Group engaged our Human Factors (HF) team. We carried out a detailed HF assessment to analyse a filter cleaning process that is associated with a MAH scenario.

SI Group wanted to understand the level of risk associated with this task, identify any recommendations, and understand if implemented would it eliminate or reduce the likelihood of human error occurring. They also recognised an opportunity to review the Human Error Probability (HEP) associated with the task, allowing them to update their Process Hazard Analyses with an assessed probability of failure on demand for the task rather than the conservative value assigned. This would support decisions regarding the benefit of any engineered solutions that could further reduce risk to operators.

Solution

Our support provided SI Group with the Human Factors expertise needed to gather regulatory guidance and relevant good practice from industry into a user-friendly procedure that was tailored to their needs. We included decision flow charts, guide questions and checklists to make assessment criteria accessible, such as task complexity, frequency, novelty and consequence. Applying the updated guidance, SI Group can be confident in their robust and proportionate approach to HF assessment, ensuring that resources are spent on the most important safety critical tasks. This has provided SI Group confidence in both their internal assessments of Major Accident Hazards and SCTs and when engaging external support as an Intelligent Customer for detailed HF assessments.

We worked with SI Group to scope a proportionate and pragmatic approach to the SCT assessment. Our experts gained an understanding of current practice by walking through the task with operators and reviewing plant documentation. The safeguards identified were all reliant on human performance and so this Human Factors assessment provided an important component of the overall safety justification. The observations and recommendations provided the opportunity for SI Group to optimise task performance and reduce the risks associated with this task.