LOPA Generic Enabling Events
LOPA Generic Enabling Events improve the consistency of Layer of Protection Analysis (LOPA) by standardising enabling event probabilities used during risk calculations. Instead of estimating enabling event values during every study, Safety Lifecycle Manager (SLM) allows organisations to define approved global enabling events once and reuse them throughout HAZOP and LOPA assessments.
By managing enabling events centrally, organisations reduce calculation inconsistencies, minimise transcription errors and ensure facilitators apply company-approved probability values across every assessment.
This guide explains what LOPA Generic Enabling Events are, how they are configured, synchronised between Enterprise and Site levels, and applied within HAZOP and LOPA studies.
What Are LOPA Generic Enabling Events?
LOPA Generic Enabling Events represent conditions that must exist alongside an initiating event for a hazardous scenario to progress to its potential consequence.
Unlike initiating events, enabling events do not directly cause a hazardous event. Instead, they influence whether the initiating event can develop into a significant consequence and therefore play an important role within Layer of Protection Analysis calculations.
Using predefined enabling events helps organisations:
- Standardise probability values.
- Reduce calculation inconsistencies.
- Improve LOPA accuracy.
- Reduce facilitator workload.
- Apply company-approved probability values consistently.
Learn more about the overall methodology in our Layer of Protection Analysis (LOPA) guide.
Configuring LOPA Generic Enabling Events
LOPA Generic Enabling Events are configured within the Global module of Safety Lifecycle Manager.
Administrators can create enabling events at either the Enterprise level or the Site level depending on how probability values are managed throughout the organisation.
- Create new enabling events.
- Enter enabling factor descriptions.
- Assign probability values for consequence categories.
- Maintain standard company probability values.
If enabling event values are consistent across every facility, Enterprise-level configuration provides the simplest approach. Where individual sites require different probability values, Site-level configuration provides additional flexibility.
Synchronising Enterprise and Site Values
One of the key advantages of LOPA Generic Enabling Events is the ability to synchronise approved values across multiple facilities.
Safety Lifecycle Manager allows administrators to:
- Synchronise Enterprise enabling events to every site.
- Synchronise Enterprise values to individual sites.
- Maintain site-specific enabling events when required.
This ensures every HAZOP and LOPA study begins with approved company probability values while still allowing controlled site-specific differences where necessary.
Applying LOPA Generic Enabling Events
LOPA Generic Enabling Events can be applied during both HAZOP studies and Layer of Protection Analysis worksheets using the same workflow.
To apply a global enabling event:
- Open the required HAZOP scenario or LOPA worksheet.
- Navigate to the Enabling Events section.
- Select the required Global Enabling Events.
- Choose Copy Global Enabling Events.
- Apply the copied enabling events to the current scenario.
Once copied into the local assessment, enabling events become available for the facilitator to apply during the risk calculation process.
Using Enabling Events in HAZOP and LOPA
LOPA Generic Enabling Events are available throughout both HAZOP studies and Layer of Protection Analysis assessments.
Using the same centrally managed enabling events across both modules helps organisations:
- Maintain consistent probability values.
- Reduce manual calculations.
- Improve facilitation efficiency.
- Reduce transcription errors.
- Improve overall assessment quality.
Because the enabling events originate from the Global module, every facilitator uses the same approved probability values during risk assessments.
Benefits of Standardised Enabling Events
LOPA Generic Enabling Events provide significant advantages when performing Layer of Protection Analysis across multiple facilities.
Key benefits include:
- Enterprise-wide standardisation.
- Consistent probability values.
- Improved LOPA calculations.
- Reduced facilitator workload.
- Improved auditability.
- Faster study preparation.
- Improved assessment consistency.
By centrally managing enabling event probabilities, organisations improve both the quality and repeatability of every LOPA study.
Learn more about the Layer of Protection Analysis Module.
Related LOPA Resources
If you’re performing Layer of Protection Analysis studies, these related guides may also be useful:
- Layer of Protection Analysis (LOPA)
- LOPA Conditional Modifiers
- LOPA Calculations
- LOPA Facilitation
- Safety Integrity Levels (SIL) Explained
For additional guidance on Layer of Protection Analysis methodology, visit the AIChE CCPS LOPA resource.
