Layer of Protection Analysis (LOPA) is a risk assessment methodology for evaluating plant hazards which provides in reducing the frequency and/or consequence severity of hazardous events with a balance between qualitative process hazard analysis (PHA) and consequences, and an order of magnitude estimate of risk.
Reference Definition by Aiche.org: Layers of Protection Analysis (LOPA) An approach that analyzes one incident scenario (cause-consequence pair) at a time, using predefined values for the initiating event frequency, independent protection layer failure probabilities, and consequence severity, in order to compare a scenario risk estimate to risk criteria for determining where additional risk reduction or more detailed analysis is needed. Scenarios are identified elsewhere, typically using a scenario-based hazard evaluation procedure such as a HAZOP Study.
Related Definitions in the Project: The Process Safety Engineering; Engineering; HSE Management
