The barrier-management approach to process safety can help organizations better understand and proactively address the risk inherent in their operations
Facilities in the chemical process industries (CPI) have many barriers in place to prevent or limit the effects of a major accident, but how do we know that these barriers continue to perform their intended function, and that their integrity is assured both tomorrow and further into the future? Further, how can we leverage a robust safety management system, what information do we need to gather, and how can these key performance indicators (KPI) drive assurance activities?
According to internationally acclaimed academic and author Andrew Hopkins, in his capacity as an expert witness at the hearing into the Longford gas explosion of 1998, “prior to any disaster, there will always be information somewhere within an organization that trouble is brewing” [1].
He expanded: “critical information must not be allowed to lie around unrecognized, ignored or buried like some landmine waiting to be triggered. The challenge is to find ways to assemble this information and move it up the hierarchy to the point where it can be understood and reacted on responsibly.”
The Longford Incident highlighted significant shortcomings in barrier management, including inadequate maintenance, insufficient robustness, lack of verification and failures in communication and overall safety culture. The recommendations from the investigation were designed to improve how safety barriers were managed and ultimately to prevent such incidents from happening in the future.
Significant strides have since been made within the process sectors, and the deployment of a more robust barrier-health system is now more commonplace. But how are engineers able to practically apply these learnings within their facilities, ensuring that the risks inherent within site operations are being appropriately managed throughout the lifecycle of the facility? This article sheds some light on these considerations.
Process safety information
The assembly of information relating to safe operation of a facility is crucial, as highlighted by Hopkins [1], and can span many departments and disciplines within an organization. This is often achieved through the implementation of a robust process safety management (PSM) system, which provides a disciplined framework for managing the integrity of operating systems and processes that handle hazardous substances.
PSM systems are routinely employed within industry, in part driven by the various frameworks and regulations which exist in different jurisdictions. These include Occupational Safety and Health Administration’s (OSHA) PSM regulations in the U.S., Control of Major Accident Hazard (COMAH) regulations in the U.K. and the Seveso III Directive in the E.U. (Figure 1). A key component in assuring safe, efficient and reliable operations is the communication throughout the organization of the critical information contained within the PSM system.
FIGURE 1. Process safety management regulations and recommendations are developed by industry-standards organizations, such as OSHA in the U.S. and COMAH in the U.K. (Image: Shutterstock)
A PSM system may be applied across your organization, but (similarly to the statement made above) how can you ensure that it is robust, that it remains so over time, and that risks inherent in your operations are being appropriately managed?
The development of KPIs, or metrics, can play a valuable role in revealing the strengths and weaknesses of a PSM program, and can help an organization work towards achieving and maintaining outstanding process-safety performance. This is of particular importance when addressing the identification and control of major accident hazards.
What do we need to know?
At a foundational level, a robust PSM system should allow us all to answer the following questions:
1. What could cause us harm?
- What hazards are inherent to our operations?
- What is present in our organization’s facility (processes, chemicals and activities) that could result in potential injuries, fatalities or significant environmental impact?
2. What will protect us?
- What barriers do we have in place to prevent these hazards from being realized (for instance, mechanical overpressure protection, instrumented shutdown systems and so on)?
- What barriers do we have in place to mitigate the severity of the consequences should they be realized (such as fire and gas detection, area classification or ignition control, emergency response plans and so on)?
3. How do we know?
- Are we confident the barriers will function as designed when required?
- What is the minimum level of performance required?
- Are these critical barriers available and effective throughout the life of our asset?
The first two points are often achieved through the application of standard risk-assessment methods (for example, HAZID, HAZOP, LOPA or bowtie analysis) whereby hazards are identified, consequences are defined and the barriers and safeguards preventing or mitigating the scenario are documented. This approach allows for a determination of whether the risks are being appropriately managed, but this determination is like a photograph, valid only at the time it was taken.
The third point challenges us further by posing the question of how we assure ourselves that these risks continue to be managed to an acceptable level throughout the lifecycle of a facility? How do we know there isn’t a proverbial landmine waiting to be triggered?
Barrier management systems
The concept of barrier management helps address this concern. The Norwegian Ocean Industry Authority (Havtil; Stavanger; www.havtil.no) states the purpose of barrier management is “to establish and maintain barriers so that the risk faced at any given time can be handled by preventing an undesirable incident from occurring or by limiting the consequences should such an incident occur” [2].
We can provide a level of assurance in the continued effectiveness of our critical barriers through the definition of minimum testing, inspection and maintenance requirements. The CPI typically capture such requirements within a performance standard for each critical barrier, but the basic logic holds regardless of application. Figure 2 provides an example flow diagram outlining how a barrier management system can be implemented for the control of major accident hazards.
FIGURE 2. Effective barrier management for process safety involves several key pillars
KPIs
The ongoing health of critical barriers can be monitored through the use of a KPI dashboard, which can provide information to help verify the following items:
- Identified preventive maintenance (PM) tasks are being completed on time
- All requirements of the performance standard are being met for each critical barrier
- The responsible or accountable persons are taking ownership of the critical barriers
Example metrics for tracking within a dashboard can include the following [3]:
- Status of assigned testing and inspection tasks (complete, due or overdue)
- Status of PM and any noted non-conformances
- Critical barrier PM backlog
- Number of PM tasks completed on any safety-critical equipment (number per time period or per critical barrier type)
Smarter tools
A range of modern business-intelligence tools may be leveraged to sustainably build a KPI dashboard, notably Radiant360, PowerBI, Scoro and Datapine. Data can be fed in real time from the computerized maintenance management system (CMMS) to populate the dashboard.
Figure 3 provides an example of how a set of barrier health metrics can be displayed in a simple, highly impactful way within a dashboard. The dashboard should be accessible to all key personnel, including process-unit and asset managers. They would typically examine the dashboard on a weekly basis to determine whether the health of the safety-critical equipment is deteriorating and, if that is the case, they know where to focus resources to restore the equipment to good health [4].
FIGURE 3. This sample dashboard shows typical KPIs for a pipeline operator
Closing thoughts
The Longford explosion highlighted a deficiency in the way in which many organizations collect and communicate key process-safety information. The definition and application of KPIs can help an organization ensure efficient assembly of this information and, more importantly, highlight and communicate this information up the hierarchy where it can be acted on responsibly.
The barrier management approach, coupled with a live KPI-based dashboard, enables risks inherent to an organization’s operations to be better understood and hence proactively managed, not only today, but throughout the future of the plant. ■
Acknowledgement
All figures provided by author unless otherwise noted
References
1. Hopkins, A., “Lessons from Longford: The Esso Gas Plant Explosion,” CCH Ltd., April 2000.
2. Havtil, Principles for Barrier Management in the Petroleum Industry, January 2013.
3. Pareschi, D., Rotating Machines: Digital Technologies to Enable Predictive Maintenance, Chem. Eng., March 2018, pp. 32–37.
4. Montgomery, R., A Holistic Approach to Asset Risk Management: Is it All or Nothing?, Chem. Eng., May 2024, pp. 35–38.
Author
James Sneddon is a director for Risktec Solutions’ operations in the U.S. (Email: [email protected]) He has over 18 years of varied risk management and technical safety engineering experience, spanning high-hazard industries, including oil and gas, civil, nuclear, clean energy and chemical processing. Prior to his role at Risktec, Sneddon held various engineering roles at SABIC. He holds an M.S. degree in chemical and process engineering from the University of Strathclyde.