BowTiePro allows users to create LOPA (Layer of Protection Analysis) assessments directly from existing hazards, threats, and consequences defined within BowTie diagrams.
Each LOPA assessment is linked to:
- A hazard
- A threat
- A consequence
This helps users evaluate whether existing safeguards reduce risk to acceptable levels.
Opening the LOPA Module
To begin:
- Log in to BowTiePro.
- From the top navigation menu, click LOPA.
The LOPA List screen will open.
Creating a New Assessment
To create a new LOPA assessment:
- Click the Create New button.
The system will open the Available Items screen.
Understanding the Available Items Screen
The Available Items screen displays combinations of:
- Hazards
- Threats
- Consequences
These items are pulled from existing BowTie hazard data.
Users can filter items using:
- Case
- Location
- Hazard
Selecting a Threat and Consequence
To create a LOPA assessment:
- Locate the required threat and consequence combination.
- Click the Create button next to the selected item.
BowTiePro will generate a LOPA assessment for that specific scenario.
Opening the LOPA Diagram
After creating the assessment, the system opens the LOPA Diagram view.
The diagram visually displays:
- Threat frequency
- Protection layers
- PFD values
- Hazard
- Consequence
- Risk calculation flow
Understanding the LOPA Diagram
The LOPA diagram provides a visual representation of the assessment.
Typical components include:
Threat
The initiating event being analyzed.
Example:
- Software does not meet requirements
Protection Layers
Independent Protection Layers (IPLs) used to reduce risk.
Examples:
- Regular peer reviews
- Functional specification review
- Software testing controls
Hazard
The central hazard associated with the scenario.
Example:
- Building Software
Consequence
The outcome being evaluated if safeguards fail.
Example:
- Loss of credibility