Guidelines for Initiating Events and Independent Protection Layers in Layer of Protection AnalysisThe book is a guide for Layers of Protection Analysis (LOPA) practitioners. It explains the onion skin model and in particular, how it relates to the use of LOPA and the need for non safety instrumented independent protection layers. It provides specific guidance on Independent Protection Layers (IPLs) that are not Safety Instrumented Systems (SIS). Using the LOPA methodology, companies typically take credit for risk reductions accomplished through