A model-based approach to operational event groups ranking

Abstract

The operational experience (OE) feedback provides improvements in all industrial activities. Identification of the most important and valuable groups of events within accumulated experience is important in order to focus on a detailed investigation of events. The paper describes the new ranking method and compares it with three others. Methods have been described and applied to OE events utilised by nuclear power plants in France and Germany for twenty years. The results show that different ranking methods only roughly agree on which of the event groups are the most important ones. In the new ranking method the analytical hierarchy process is applied in order to assure consistent and comprehensive weighting determination for ranking indexes. The proposed method allows a transparent and flexible event groups ranking and identification of the most important OE for further more detailed investigation in order to complete the feedback.

Uncertainty Analysis of Method-Based Operating Event Groups Ranking

“…where RI is ranking index, EG is event group, and is weights for respected parameter. These weights could be judged by experts directly or more transparently and consistently by using some methods like the analytical hierarchy process (AHP, [3,5]) where the only requirement is to make pairwise comparisons for all parameters. Table 2 presents a set of RI weights used in Table 3).…”

“…(Selected results are presented in the Table 4 for the FR and Table 5 for the DE datasets under column "AHP point. ") separately and this analysis applies to the AHP based ranking method, [3]. Uncertainty of dataset values is considered outside this assessment because it is epistemic and not significant (in comparison to the ranking uncertainties).…”

“…Using Analytical Hierarchy Process (AHP). This is a short description of the application of the analytical hierarchy method for the determination of ranking indexes relative importance in the event group ranking assessment (modified from [3]). Methodical approach is applied in order to allow easier and more consistent RI weighting determination for the expert.…”

“…In [3], four different approaches for event groups ranking were compared with findings about their difference and proposed favorable method. The selected method is based on the application of the analytical hierarchy process in order to allow easier determination of relative importance for all ranking indexes (RI).…”