In this session, the participant will learn about Process Safety Management in general and more particularly about what is Process Safety. We will present a concrete definition of what a Safety Instrumented System (SIS) is. This involves important concepts such as risk, Safety Integrity Level (SIL), Lifecycle and protection layer. We will also look at why does major accident happened and keep happening. This will lead the discussion about the business case for Process Safety and about the key elements of Process Safety Management. This will address the lifecycle management of a process in regard to Safety Instrumented System (SIS) and how to address the GAP between “as designed and installed” vs “as operate and maintained”, the impact of proof test, demand rate, the cause and frequency of spurious trips. We will close the session talking about how plant can ensure continuously safe and reliable production.