Each month at exida, we strive to spotlight one of our products that makes the job easier for today's industry professional. In this blog, I wanted to talk about the exida publication  Practical SIL Target Selection - Risk Analysis per the IEC 61511 Safety Lifecycle which is based on numerous courses, seminars, and safety engineering projects exida has completed throughout the world. This is a must read book for Process Safety Engineers, SIL Determination/Selection Engineers, PHA & LOPA facilitators. 

The first phase of the safety Lifecycle is the Analysis phase. During this phase, users are expected to identify hazards, analyze the risks associated with those hazards, and compare the determined levels of process risk with tolerable levels. If the process risk is larger than the tolerable risk, risk reduction must be implemented. Determining the amount of required risk reduction is referred to as SIL Target Selection.

Risk analysis per the IEC 61511 Safety Lifecycle revolves around establishing target SIL levels for Safety Instrumented Functions. The Practical SIL Target Selection - Risk Analysis per the IEC 61511 Safety Lifecycle book describes aspects of risk management and establishing a level of tolerable risk. The book describes concepts of consequence analysis and likelihood analysis including qualitative and quantitative Layer of Protection Analysis (LOPA). Consequence and Likelihood together define (process) risk. It also describes methods to determine required risk reduction through methods like risk matrix, risk graph, and frequency based target options.

Highlights of the book also includes:

• Expands upon framework developed in functional safety standards
• Provides a working guide to apply SIL Target Selection concepts and techniques
• Applies to both retrofit and green field projects in the process and machine automation industries.