Calculators›LOPA
📊

LOPA Analysis Toolkit

CCPS / IEC 61511

LOPA Risk Assessment Calculator
Quantifies risk reduction from independent protection layers (IPLs) and determines SIL requirements per IEC 61511/ANSI/ISA-84. Calculates mitigated event frequency using CCPS methodology with standard PFD values for process industry safeguards.

Scenario Definition

e.g., V-101

Initiating Event & Enabling Conditions

0-1
0-1
0-1

Independent Protection Layers (IPLs)

0.0001-1

📚 Learn the Theory

Learn LOPA methodology, IPLs, PFD calculations, and SIL determination

Read Engineering Guide →

About This Calculator

Layer of Protection Analysis (LOPA) is a semi-quantitative risk assessment method per CCPS Guidelines and IEC 61511/ANSI/ISA-84.

LOPA Equation:

fmitigated = fIE × PEC × PFD1 × PFD2 × ...

Key Terms:

  • fIE: Initiating event frequency (/yr)
  • PEC: Enabling conditions probability
  • PFD: Probability of Failure on Demand
  • RRF: Risk Reduction Factor = 1/PFD

Standards:

  • IEC 61511 / ANSI/ISA-84
  • CCPS "LOPA" Guidelines (2001)
  • CCPS "Initiating Events & IPLs" (2015)

Frequently Asked Questions

What is the LOPA Calculator?

It performs Layer of Protection Analysis (LOPA) for process safety and SIF determination per IEC 61511.

What standard does this LOPA tool follow?

The LOPA Calculator follows IEC 61511 for safety instrumented function determination.

What is Layer of Protection Analysis used for?

LOPA is used for process safety assessment and determining the required safety integrity level of protection layers.

Related Calculators

⚠️

HAZOP Analysis

Hazard identification and operability study
🔥

Consequence Modeling

Model fire, explosion, and toxic dispersion
🔧

Relief Valve Sizing

Size pressure relief valves per API 520/521
⏱️

Blowdown Analysis

Emergency depressurization system design