Major accident hazards in the gas industry

George Petrie describes how TEPUK has used human factors principles to reduce potential for human failure in the gas industry

In the oil and gas industry, the importance of human failures as an accident causation factor is well known. Historically, the focus has been primarily on identification and prevention of technical failures causing major accident hazard events (MAH) with less emphasis on the role of human failures.

In order to address human failures in potential MAHs, TOTAL E&P UK (TEPUK) has developed a process to manage the risk of human error across their onshore and offshore assets. This journey over the last few years has not been an easy one, but by developing sound foundations the company has started to show significant benefits in managing human failures in MAH scenarios.

How are we implementing change?

TEPUK decided that a move to focus on Human and Organisational factors (HOF) in process safety required a competent person, that is, a member of the CIEHF, to be embedded in the safety engineering department rather than within traditionally the occupational safety department.

The methodology chosen was to follow the guidance produced by the HSE in their Roadmap for safety critical task analysis. In order to implement this, a number of in-house procedures were developed to ensure a consistent approach was used across the company.

The first step in the roadmap process was to identify the MAH scenarios where HOFs influence the outcome. From a human error point of view, the definitions and detail of MAH scenarios in the guidelines were open to a certain amount of interpretation. In order to identify the MAH scenarios in a robust and consistent manner, TEPUK held a series of workshops facilitated by an experienced external risk management consultant. These workshops involved engineers from TEPUK’s safety engineering department who reviewed various MAH scenarios to develop and test a defined methodology appropriate for the company.

In order to identify the MAH scenarios at each operational site, the first step involved a workshop covering each designated plant area. During the workshop, a review of the site Control of Major Accident Hazards (COMAH) Report and corresponding safety studies such as the Hazard and Operability (HAZOP) study was the main focus of activity. The output from this process identifies the specific involvement of people in the relevant activity associated with the upkeep of each prevention, mitigation or control barrier.

To complete the task analysis process, it is essential to involve internal technical support from the human factors engineer, safety or process engineers and most importantly the supervisors, operators and technicians who carry out the tasks.
The human error analysis actions have been followed up in number of ways, depending on severity:
Where significant risk is found as a result of human error, specific studies are carried out to identify if further engineering controls are required.

Where procedural controls are required, stop/hold points are added at the specific steps in the procedure that highlight the hazard effect and risk control measures. This also requires a counter signature by a second person before proceeding.
Where an occupational safety hazard is found, a safety, health, environment and operational integrity note is added explaining the hazard and risk control measures at that specific point in the task.

The checklist for the performance influencing factors was developed after reviewing guidance and it is imperative that this allows a consistent approach when walking through the tasks on site. After completion of the new procedure a review of training and competency is carried out. This requires a clear link between the task, training requirements and competency to ensure human error is minimised.

How far are we on the journey?

The whole process has gained momentum at TEPUK’s onshore gas plant, with resources being allocated to support the assessment process and to facilitate updates to site procedures.

During the workshops, a number of scenarios were identified where a single error could lead to a MAH. Various operators recognised that they were not aware of the possible scenarios following these errors. These scenarios are now the focus of HAZOP studies and also changes to the isolation procedures to include STOP/HOLD points and full details of the hazard effect and the risks. The STOP/HOLD points are placed at specific task steps and highlighted in order that operators or maintenance techs have clear information at the appropriate step in the task rather than a generic statement at the beginning of the procedure or mentioned in a separate work permit. This simple step allows increased control of potential human error as an counter signature is required by a second person prior to the task proceeding to the next step.

As this subject is not widely understood by people who are not human factors professionals, TEPUK developed specific awareness training courses. Leaders attend a two-day course facilitated by external consultants and the in-house HF engineer, while operators/technicians attend a shorter awareness course of approximately two hours. Feedback from this latter course has highlighted that we need to lengthen the time allowed. These courses are fully aligned with the safety critical task analysis process using site based examples to help explain the principles throughout the training. The process requires a large amount of resources and subsequent support and investment from management, and is now progressing well across TEPUK with plans to involve project and modification engineers.

Lessons learned and conclusions

Developing and implementing this process has been challenging and the following explain some of the learning points identified:
- Organisations need to be intelligent customers and choose HF consultants that fulfil the competency requirements of the CIEHF.
- A clear strategy and common methodology is required. We found that without a TEPUK common process, results obtained were not consistent across the various operational sites.
- Focus on major risks. The process is more effective when priority is given to MAH scenarios that are deemed high risk from human error.
- Close the loop from MAH scenarios right through to training and competency. The higher level of detail required in documentation for high risk tasks must fully align with the actions identified from human error analysis and be linked to training and competency for that task.
- Integrate HF into the business, ensuring the workforce and management have sufficient knowledge and understanding of human and organisational factors.
- Involve the employees. The initial studies, which were not particularly successful, were conducted mainly as desktop studies.

These were found to be largely ineffective in understanding how a task is carried out. As a result, TEPUK always involve the workforce at each step in the process. This has resulted in significant benefits being realised both with employee buy in and their improved understanding of the issue.

TEPUK future plans, 2015 and beyond

This entire process is still very much a work in progress but the foundations have been developed. TEPUK have focused their efforts on high risk tasks at each operational site as a priority until these have been fully addressed. Once complete, progress will be made on those remaining tasks identified as medium and low safety critical tasks.

One benefit from implementing this approach has been the subsequent identification of situations where risks of human error could affect the validity of environmental permits and consents, adversely impact operational downtime, potentially damage equipment or impact future business continuity. Due to the business value of addressing these issues, they will be incorporated and further developed in future plans.

By George Petrie, Lead Human Factors Engineer at TOTAL E&P UK

This article was first published in issue 538 of The Ergonomist, April 2015

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