Layer of ProtectionAnalysis
Nigel Hyatt · 2018
Layer of Protection Analysis (LOPA) introduces the concept that protection against an untoward or serious consequence, such as fire, may not simply be at a single level, or layer, but rather that there are likely to be multiple levels or layers of protection. Consider, by way of example, a fire situation. The Emergency Shutdown System (ESD) will constitute one layer, the Pressure Relief and Flare System will constitute another layer, the Fire Protection System involving deluge will be another layer, Emergency Response another layer and so forth. The analysis of the layers is referred to as LOPA. Figure 2 1-1 illustrates some common layers of protection for a process.