(90a) Set Your Operators up for Success: Practical Guidelines for Addressing Human Factors in PHA Causes and Protection Layers

Everyone makes mistakes. Therefore, every Process Hazards Analysis (PHA) should address the potential for human error when people interact with a process facility. It is unreasonable, however, to ask a PHA team to address every error that could be made by a person, so guidance must be given on the types of human factors to address.

Momentary errors, larger mistakes and intentional violations are all types of human factors that could result in a hazardous scenario, or prevent a protection layer from working correctly during a critical scenario. A PHA must consider human error in the identification of causes, and assigning safeguards or protection layers, but this must be done in a way that keep the quality and efficiency of the PHA session at a high level.

Effectively addressing Human Factors into PHAs will help to identify and protect against hazardous events that could be caused by someone making a mistake, and to catch and fix scenarios in existing or new facilities that may push someone to ignore procedures or take a “short-cut”. In order to do this, it is essential to understand why people take these incorrect actions. Once this is understood it is possible to address them effectively with a lasting improvement, rather than providing “band-aid” short-term solutions.

This paper will investigate the types of errors and violations people make, and discuss the reasons that people act in this way. It will then explain how to effectively incorporate this knowledge into a plan for addressing Human Factors in HAZOP and LOPA, when identifying potential causes of hazardous scenarios and in deciding which protection layers to rely on, by drawing on the author’s experience of facilitating over 180 PHAs for a wide variety of petrochemicals and processing companies throughout North America.