If you are like most risk professionals who are using BowTieXP, you have used the software to create visuals of the risks that your organization is dealing with.
You improved understanding of potential risk scenarios around hazards in your organization, and how you intend to manage those risks by implementing barriers. Looking at the plan-do-check-act cycle, you’ve completed the first two steps. Now it’s time to check whether your barriers are functioning as you intended.
One way to do that is by conducting barrier based audits. CGE Risk partner SynergenOG, a company that is specialized in Process and Operational Safety Management has recently started an auditing project at a large downstream petrochemical organization. Below they will share their best practices on what steps a barrier based audit should entail.
Guest blog by SynergenOG Sdn Bhd
The design of modern-day processing facilities typically includes the provision of physical safety barriers in the form of hazard prevention/mitigation systems such as:
- Fire and Gas detection networks
- Firewater sprinklers
- Lifeboats/life rafts (for offshore-based facilities)
- Safety signage
- Emergency lighting
Generally, the site owner is duty-bound to implement, as far as reasonably practicable, necessary measures to ensure the safety and health of its employees at work, which includes a thorough assessment of (provision and maintenance) of plant and system of work.
Problem statement: how to gauge reliability of safety barriers
Nevertheless, as with most things, not all barriers are created equal, with some having a greater or less degree of effectiveness for a particular hazard than others. The effectiveness of the aforementioned safety barriers as the facility enters the operations phase is mainly dependent on how systems are being operated and maintained. A common consideration arising throughout facility operations is: “How do we gauge the effectiveness/reliability of our safety barriers throughout the plant lifecycle?”. Often effectiveness is prescribed subjectively by the site owners based on preconceptions or assumptions, which can be overly optimistic.
A commonly used objective technique for determining barrier effectiveness are assurance audits, whereby for each barrier, a representative sample size of personnel responsible for the barrier is audited. However, the difficulty of this exercise can increase exponentially as our plant facilities increase in complexity, and the role of personnel within the upkeep of safety barriers becomes less clear.
Measure barrier effectiveness with barrier based audits
SynergenOG has recently assisted a client in undertaking an assurance audit of their recently constructed petrochemical plant to gauge the reliability of safety systems put in place. Therefore, the audit scope was primarily focused on systems deemed essential to prevent or limit-effect of fatal hazards, otherwise defined as safety-critical barriers. Throughout the design of this facility, all Major Accident Hazards were identified from Hazard Identification (HAZID) workshops and presented in a bowtie diagram. This enables a clear illustration of the major hazards alongside the respective threats, consequences, and critical safety barriers.
Having this clear barrier picture, SynergenOG was asked to conduct a barrier assurance audit before the commencement of plant operations to obtain a definite view on the barrier effectiveness within the current plant design and operations. Considering this is a new plant, the intention was to survey user’s knowledge of the barrier, how it is operated, monitored, and maintained on the ground. This audit involved gathering feedback and input from a broad sample size of hundreds of operators, supervisors, engineers, and the management, which is challenging.
To conduct this project, SynergenOG turned to the AuditXP tool within the BowTieXP software suite, which allows us to:
- Generate survey questionnaires for each role function
- Assign individual questions to respective safety barriers within the Bowtie diagram
- Create appropriate question response rulesets for each question
- Collecting questionnaire responses to determine the effectiveness of the barrier (i.e. if the majority of questionnaire responses were positive in nature, this would indicate that the barrier effectiveness is strong and vice versa)
- Visualize the status of the barrier – color coded according to their level of effectiveness for improved visualization
This project involves three (3) main stages:
Stage 1 – Preparation
At this stage of the audit, preparation involves:
- Tabulate list of safety barriers;
- Identifying person responsible for a particular barrier;
- Identifying procedure(s) in place to maintain a barrier;
- Subdividing the client team into groups following their respective job function and responsibility;
- Brainstorming questions to be applied to each barrier will prompt the auditee to give us an insight into the barrier condition. Such an exercise is carried out in conjunction with the client team to furnish comprehensive information to fully understand processes in place on barrier management and develop an effective questionnaire.
This project’s scope involved assessing 11 fatal accidents and approximately 90 barriers that are deemed essential. We developed over three hundred (300) questions and subdividing the client team into 20 groups, and questions assigned to each group ranged from 20 to 100 depending on their job scope. If time permits, it is best to limit the number of questions answered each time and have it completed in batches. In that way, the participant will remain focused on answering the questions.
