Layer of Protection Analysis

  • “Layer of Protection Analysis: Simplified Process Risk Assessment”, CCPS/AIChE, 2010
  • Standard IEC-61511 –functional safety instrumented systems for the process industry sector – part 3: Guidance for the determination of the required safety integrity levels – appendix F”. First edition, IEC, 2003

Layer Of Protection Analysis – LOPA is a semi-quantitative tool for risk assessment, strictly connected with HAZOP analysis, and, in particular, it is addressed to evaluate the effectiveness of prevention and mitigation systems, basing on risk acceptability criteria.

As an additional purpose, LOPA allows to allocate SIL level for Safety Instrumented Functions (SIFs).