Overview

Overview of the Layers of Protection Analysis (LOPA) Module

Layers of Protection Analysis (LOPA) is a type of risk assessment that helps you evaluate the frequency of occurrence of events that can cause a hazard, the likelihood of failure of independent layers of protection, and the consequences, to provide an estimate of risk associated with a scenario. LOPA is a fully quantitative assessment of risk and applicability of safeguards.

The Layers of Protection Analysis module is complementary to Hazards Analysis and SIL Assessment. It uses GE Digital APM core functionality to create and manage LOPA. The LOPA assessment can help in:

  • Evaluating scenarios generated in the Hazard Analysis.
  • Identifying safeguards that can act as an Independent Protection Layer (IPL).
  • Determining the Safety Integrity Level (SIL) for Instrumented Functions.

You can use the integration between the Layers of Protection Analysis module and SIS Management module, and the integration between the Layers of Protection Analysis module and Hazards Analysis module, to centrally manage LOPA for various scenarios and safety systems.

Access the LOPA Overview Page

About This Task

By default, the hierarchy level is set to Home and the information that appears on the LOPA Overview page is related to all Hierarchy Levels, including records that are not associated with any Asset. You can filter the information that appears on the page based on a specific Asset by selecting on the upper-left corner of the page.

Procedure

In the module navigation menu, select Integrity > Layers of Protection Analysis.

The LOPA Overview page appears, displaying the following tabs:

  • Under Review: Contains a list of LOPAs that are being reviewed and have not been approved. This sections contains the following columns of information:

    • LOPA ID: Contains the value from the LOPA ID field. You can select the link in the LOPA ID column to access the LOPA.
    • Initiating Event: Contains the value from the Initiating Event field.
    • Frequency of Initiating Event: Contains the value from the Frequency of Initiating Event field.
  • Approved: Contains a list of LOPAs that are approved (i.e., in the Complete state). The section contains the same columns of information as the Under Review tab.

LOPA Workflow

This workflow provides the basic, high-level steps for using the Layers of Protection Analysis module. The steps and links in this workflow do not necessarily reference every possible procedure.

  1. Create a Layers of Protection Analysis by defining the type of Initiating Event, the required mitigated consequence frequency, and the probability of the enabling event. You can also associate the LOPA with a Functional Location and an Equipment.
  2. Create Conditional Modifiers and define their probabilities.
  3. Create Safeguards by defining the Safeguard type and linking an Asset to the Safeguard.
  4. Specify a Safeguard as an Independent Protection Layer (IPL).
  5. Evaluate the results by viewing the summary in the LOPA Summary workspace of the LOPA.