Human Independent Protection Layers (IPLs) rely on operators to take action in response to alarms or during routine system checks to prevent undesired outcomes. While human performance is generally less

The safety lifecycle approach recognizes that there are two fundamentally different ways in which the SIS can fail to perform its intended function. These are known as random and systematic

A failure occurs when a device at some level (a system, a unit, a module, or a component) fails to perform its intended function. Each safety instrumented function (SIF) in

A Safety Instrumented System (SIS) is a control system consisting of sensors, one or more controllers (often referred to as logic solvers), and final elements. Another common name is an

What is a Safety Instrumented Function (SIF)? A Safety Instrumented Function (SIF) is a system designed to reduce risks associated with specific hazards by taking an automatic action when required

Safety Integrity Level (SIL) is a quantitative target used to measure the level of performance required for a safety function to achieve tolerable risk for a process hazard. Defined in

The Probability of Failure on Demand (PFD) is a critical metric in safety and reliability engineering. It quantifies the likelihood that a system or Safety Instrumented Function (SIF) will fail

Layers of Protection Analysis Methodology  LOPA (Layers of Protection Analysis) is a semi-quantitative method used to evaluate and analyze risk scenarios with significant consequences or the potential for major accidents.