Sensitivity analysis in lightning protection risk management

The total risk R can be expressed by the following equation: R = NPL, where N is the number of dangerous events, P is the probability of damage and L measures the amount of loss. These parameters can be regarded as macroparameters in the sense that they can be given as a function of additional parameters (microparameters). Methods of calculation, check and refinement of parameter values have always been general themes of the standardization. The comparison of standards IEC 62305-2:2006 Ed. 1 and IEC 62305-2:2010 Ed. 2 is a good example of these efforts, as changes underwent in the determination of the collection area of service and the value of some parameters, moreover new parameters were introduced in order to break existent parameters into more components. Though the international standard contains the value of parameters, it does not give any information about the procedure how these values were determined, nor about the theoretical considerations behind. Therefore it is proper to ask whether the changes of a given parameter value or introduction of a new parameter make radical changes in resulting risk value or not. In this study sensitivity analysis was used to investigate how the individual macro- and micro parameters influence the risk. Moreover it was determined whether or not new parameters and calculations have an effect on the importance of the respective components of the resulting risk. The sensitivity analysis was done for two case studies in the standard, a country house and an office building respectively, with both editions of the standard. (C) 2013 Elsevier B.V. All rights reserved.