Optimizing Process Safety

The Transformative Power of Integrated Software to Improve Process Safety Situational Awareness.

Process safety is a crucial aspect of industrial operations, encompassing various elements that work together to reduce the likelihood and severity of incidents. From process design to procedural safeguards, each layer of defense plays a critical role in ensuring the safety of personnel, the environment, and neighboring communities. In this blog post, we have collaborated with Rob Trout, Principal Consultant at ATSYS, to explore process safety challenges and potential barriers organizations can implement to strengthen their process safety systems. We’ll also discuss innovative tools like safety bowties to help visualize safety barriers and enhance overall safety performance within industrial operations.

The Challenges with Process Safety

Process safety includes various elements. Each layer of defense in process safety represents a crucial barrier or safeguard that reduces the likelihood or severity of incidents. These barriers encompass a wide range of elements, from inherent safety features in process design to procedural safeguards such as operating procedures and training. Alarms, emergency response plans, and physical protection barriers further contribute to a multi-dimensional defense-in-depth approach.

Figure 1. This diagram shows the Layers of Defense usually employed to prevent major process safety incidents. (click here to enlarge)

However, these barriers’ effectiveness relies on their design, implementation, and maintenance, and the organizational culture that supports their integration. By examining process safety through the lens of these barriers, stakeholders can identify gaps, strengthen defenses, and enhance overall safety performance within industrial operations.

The Layers of Defense

These nine layers of defense are categorized into the Prevention Layers and Mitigation Layers, as shown in the diagram below:

Figure 2. Preventative and mitigating defences preventing the worst case scenarios. (click here to enlarge)

Prevention Layers are designed to prevent accidents from happening initially, while Mitigation Layers are intended to prevent or at least minimize the overall consequences when a loss of hazard containment occurs.

Barriers play a crucial role in process safety systems by offering layers of protection against hazards, reducing risks, and mitigating the consequences of accidents. Ultimately, they ensure the safety of personnel, the environment, and neighboring communities. Let’s explore some potential barriers.

Process Design Barrier
Examples of Barriers

Plant equipment designed (or devices installed) to reduce process risks
Eg: Pump impellor is sized smaller to prevent overpressure

Weaknesses

This information is often hidden or not widely known
These items wear out and need to be replaced
Subject to changes or improvement projects

Strengthening Solutions

Managing changes through an MOC process
Visibility or documentation of these design features

Basic Process Control System (DCS/SCADA) and Alarms & Operator Intervention
Examples of Barriers

Process Controls
Process Alarms with correct operator response

Weaknesses

Easily modified
Process Controls can be switched off
Alarms can cause nuisance, or alarm flooding
Alarms can be disabled, shelved or switched off
Sensors can drift and become inaccurate over time

Strengthening Solutions

Implement Alarm management (ISA 18.2)
Provide alarm help information to operations
Capture operator response times vs Alarm Philosophy
Alarm metrics and history analysis
Warning of excessive alarms or long-term inactivity

Safety Instrumented Systems (SIS) and Safety Instrumented Functions (SIF)
Examples of Barriers

High-pressure shutdown
Automatic safety functions (SIFS) to shutdown process
Safety Integrity Level (SIL) targets for redundancy & resilience

Weaknesses

SIFs don’t usually operate, so regular testing is required
SIF testing is prone to human error
Functions may be overridden or bridged out
Diagnostic information often not visible

Strengthening Solutions

Highlight barrier in real-time if overridden or bridged out
Highlight SIF testing non-compliance
Real-time monitoring of SIF activations & track responses for compliance
Historical SIS performance metrics for analytics & insights

Physical Protection Barriers
Examples of Barriers Process Safety Valves

Bunds or walls
Bollards

Weaknesses

Not usually monitored
Degrade over time
Require regular scheduling of inspections or test

Strengthening Solutions

Alerts/highlight if inspections or tests are behind schedule
Past inspection or test reports with photos readily available
Barrier status is updated manually based on these reports
Barrier status made visible to the entire organization

Solving Process Safety Challenges

The key to improving process safety is to consolidate data from various sources into a single platform. By integrating multiple systems and processes, organizations can monitor overall process safety in real-time. This not only improves safety outcomes but also simplifies management processes, reduces paperwork, and eliminates time-wasting activities. However, despite advancements in process safety management, challenges persist. One of the pressing concerns is ensuring that every element of the safety system functions effectively when needed. To overcome these challenges, organizations can leverage available data to visualize safety barriers through innovative tools like safety bowties.

Bringing Bowties to Life

Safety bowties offer a concise yet comprehensive visualization of potential hazards, associated consequences, and the preventive and mitigative barriers in place. This visual representation facilitates clear communication of risks across all levels of an organization, enhancing understanding and promoting a proactive approach to safety. By considering data requirements such as real-time capability and integration with existing systems like process control systems and document management, organizations can enhance their understanding of risks and promote a proactive approach to safety.

As industries continue to prioritize safety and regulatory compliance, the adoption of safety bowties is expected to persist and expand, driving improved safety outcomes and reducing the likelihood of major incidents.

Imagine a situation where a manager can view a process safety dashboard where all existing bowties depicting the various top hazardous events are shown in a color-coded method based on the current stats of their prevention barriers. Let’s look at a generic, typical bow tie below:

Figure 3. An example of a Live Process Safety Bowtie Diagram illustrates the concept with colors identifying abnormal situations. (click here to enlarge)

The top Hazard is shown in RED because there is an increased risk of a catastrophic event. In the case above, it may be due to one of the consequences highlighted red. But this manager can also see that one of the preventative barriers is showing as yellow (a degradation of the barrier).

Drilling down into that barrier, the software presents either a pop-up or slide-out window that allows drilling into that specific barrier as shown below:

Figure 4. Drill down to more detail to discover the factors which may cause barrier failure or degradation, and visualize the status of the controls in place to prevent degradation. (click here to enlarge)

In the example above, the degradation controls for that barrier shows that the Safety Instrumented System alarms have not been recently tested. Such demand or proof testing of the SIS is often also a regulatory compliance requirement and as such, the risk of a highly consequential event is also coupled with the risk of the loss of right/license to operate (by the authorities).

Benefits of a Live Safety Bowtie

Implementing a live safety bowtie offers several primary benefits that contribute to enhanced process safety. Firstly, it helps prevent the degradation of process safety barriers and fosters a heightened awareness within the organization regarding the status of these barriers. Additionally, by employing a live bowtie, there is a substantial reduction in manual effort required for monitoring safety barriers. This approach also aids in achieving compliance with regular maintenance and testing schedules, leading to improved training and awareness of process safety barriers. Furthermore, it enhances the quality of Management of Change (MOC) processes and risk assessments by providing access to more up-to-date information.

Conclusion

Process safety is a continuous journey that requires a proactive and integrated approach. By embracing innovative solutions, leveraging data effectively, and prioritizing a culture of safety, organizations can enhance process safety performance, protect personnel and the environment, and ensure the sustainability of industrial operations.

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