(153a) Integrating Layer of Protection Analysis within Process Hazard Analyses – 24 Years Later

Twenty-three years ago, a paper titled “Integrating Layer of Protection Analysis within Process Hazard Analyses” was presented at the Center for Chemical Process Safety (CCPS 17^th International Conference and Workshop). Since that time, many companies have adopted incorporation of Layer of Protection Analysis (LOPA) within their Process Hazard Analyses (PHA). A simplified risk assessment approach such as LOPA continues to help companies by providing a thorough and consistent method of risk evaluation, critical safeguard identification and Safety Integrity Level (SIL) assignment to safety instrumented functions (SIFs). Incorporating simplified LOPA into the PHA, provides an “order of magnitude” estimate of risk that can be completed simultaneously during a PHA, hereby reaping the benefits of LOPA without taking significant additional time or resources other than those already needed to complete the PHA.

This paper will discuss how original authors of the “Integrating LOPA within PHA” paper have implemented this methodology over the last 23 years, including case studies. In addition, the authors will include feedback from interviewed representatives from companies where the authors originally implemented LOPA within the PHA to assess how the methodology is practiced today with respect to design of new facilities, PHA revalidation of existing processes and design of safety instrumented systems (SIS). This paper is of significant interest to industry leaders responsible for Process Safety Management (PSM) and Risk Management (RM).