GPA Midstream Fall Technical Conference: Reducing human error in gas pipeline operations
By Adrienne Blume, Editor-in-Chief, Gas Processing & LNG
At the virtual 2020 GPA Midstream Fall Technical Conference on Thursday, Jill Watson, Senior Probabilistic Risk Engineer at Enercon in Texas, provided a working-level understanding of human reliability analysis for gas pipeline operations.
Jill Watson, Senior Probabilistic Risk Engineer at Enercon in Texas
One of nine PHMSA pipeline threat categories that are required to be addressed under an integrity management plan is incorrect operations (IOs). This threat occurs as a result of an operator action that results in an unintended consequence due to human error.
IOs resulted in approximately 6% of significant events and around 8% of non-significant events that occurred during pipeline incidents from 2010 to 2013, Watson noted. Both significant and non-significant IOs can be addressed through a comprehensive human reliability analysis (HRA). HRA is the incorporation of human "contributions" into the analysis of safety and risk. The results derived from performing an HRA can be used to improve operator responses and reduce human errors.
Mitigating human error. PHMSA risk guidance published in February 2020 states that operator actions and IOs are a leading contributing cause of pipeline incidents. "Audits show that humans don't always diagnose or execute actions correctly, even if they have perfectly written procedures," Watson explained. "We need to find a better way to advance human performance in completing critical tasks and providing additional administrative controls in order to provide safety and quicker responses in the gas industry."
Error-reduction tools and well-written documentation and procedures are essential. Such tools and procedures include awareness training, self-checking and peer-checking, procedure steps defined with action verbs (e.g., "close," "verify," "check"), short series of listed steps in dual-column or checklist format, and place-keeping or sign-off for tracking steps.
Examining human reliability. Industries that already use HRA include nuclear, offshore oil and gas, aerospace, pipeline, aviation and chemical production. A number of factors can cause human errors, including adverse environmental conditions, unclear roles or responsibilities, fatigue, time pressures (especially in facility control rooms), high workloads, confusing displays or controls, and lack of clear directives.
Human errors can result in a reduction of system reliability and/or safety margins, increased risk, or degraded conditions. The HRA method is a structured approach used to identify potential human failure events (HFEs) so that they can be prevented.
Watson shared an example HRA, wherein a study of operator actions was completed using pipeline procedures to identify critical human interactions; potential errors of commission, omission and cognition; and performance-shaping factors.
In performing an HRA, safety-related actions or critical tasks performed by operators and plant personnel must first be identified, Watson explained. The procedures required to execute these actions and critical tasks are then outlined and analyzed. Finally, these procedures are revised for clarity and simplicity in light of the risk of associated human errors. The HRA method can help improve facility operations and personnel safety.
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