The use of the Pareto shape parameter as a leading indicator of process safety performance

Metrics addressing process safety incident performance typically focus on frequency and severity statistics. Often, these lagging metrics are not overly sensitive to actual performance, making trending and forecasting difficult. This article presents the results from a statistical study of a large incident dataset where changes in the Pareto shape parameter were observed as a function of time. This approach has been found to give far better insight into process safety performance than traditional incident metrics and readily relates back to concepts such as the “incident triangle” and “layers of protection.” Through the application of this approach, trends within process safety incident performance have been observed earlier, and more accurate forecasting has allowed for the identification of anomalies. In turn, these critical observations have allowed for the better structuring and targeting of process safety programs. Although incident data are generally considered as a lagging indicator, this approach has clearly reduced the lag time associated with this type of data and has given valuable insight into the current status of process safety performance. © 2009 American Institute of Chemical Engineers Process Saf Prog 2009