Layers of Protection Analysis (LOPA)
Layers of protection analysis (LOPA) is a powerful analytical tool for assessing the adequacy of protection layers used to mitigate process risks in the installation. LOPA builds upon well-known process hazards analysis techniques, applying semi-quantitative measures to the evaluation of the frequency of potential incidents and the probability of failure of the protection layers.
Layers of Protection Analysis (LOPA)
Layer of Protection Analysis (LOPA) is a semi-quantitative method for process hazards analysis. According to ANSI/ISA-84.00.01-2004 Part 3 (IEC61511-3 Mod), “The method starts with data developed in the Hazard and Operability analysis (HAZOP study) and accounts for each identified hazard by documenting the initiating cause and the protection layers that prevent or mitigate the hazard. The total amount of risk reduction can then be determined and the need for more risk reduction analyzed. If additional risk reduction is required and if it is to be provided in the form of a Safety Instrumented Function (SIF), the LOPA methodology allows the determination of the appropriate Safety Integrity Level (SIL) for the SIF