LOPA 104: Layer of Protection Analysis

COURSE DESCRIPTION                                                                                  DURATION: 2 Days

In this course, the participant will learn about, Layer of Protection Analysis (LOPA) which is a semi-quantitative risk assessment method that that lies between a qualitative process hazard analysis and a traditional quantitative risk assessment. This technique also helps in determining the Safety Integrity Level necessary for a safety instrumented system to comply with instrument standards such as ISA S84 and IEC 61511.  This course will cover the LOPA methodology in detail through practical examples and teach fundamental rules of how to develop LOPA scenarios, estimate their consequences and severity, identify initiating events and frequency, and finally calculate risk and make decisions. In this course, the participants will learn about the independent layers of protection in the real sense and estimating their failure on demand. This course will also demonstrate practical examples to explain each concept and the development of a LOPA worksheet from a PHA worksheet.


  • Learn how and when to use LOPA
  • Learn to create scenarios for new processes or existing facilities undergoing change from PHA study
  • Learn how to determine the independence and uniqueness of an Independent Protection Layer
  • Learn how to lead a LOPA study
  • Learn industry best practices for LOPA

  • Experienced PHA/HAZOP leaders and PSM Coordinators and Managers
  • Operations, Safety and Project Managers; Process, Safety and Mechanical Engineers

  • PSM or PHA training



Day 1

  • Process Safety Concepts
  • Introduction to LOPA
    • Overview of LOPA methodology
    • When is LOPA used?
    • Uses  and Limitations of LOPA
  • Risk and Risk Tolerance Criteria
    • Examples of Common Risk Matrixes
  • Development of LOPA Scenarios
    • Selection of Hazard Scenarios using Hazard Evaluation
    • Selection of Hazard Scenarios using Previous Incidents
    • Selection of Hazard Scenarios from Design Evaluation
  • Estimation of Consequences and Severity of Scenarios
    • Consequence Categories
    • Defining severity for the consequences
Day 2

  • Identification of initiating events
    • Understanding Initiating Events
    • Initiating Event Frequency Estimation
    • Enabling Conditions and Conditional Modifiers
  • Identification of Independent Protection Layers (IPL)
    • Types of IPL
    • IPL Assessment
    • Estimating Probability of Failure on Demand of IPLs
  • Calculating the Risk
    • Use of LOPA Worksheet
    • Calculation of Risk for scenarios
  • Making risk decisions
    • ALARP and its typical application
  • Performing PHA to facilitate LOPA
  • Example Workshop