Use of AHP for risk based fatigue degradation inspection analysis of topside piping on offshore production and process facilities

Currently, a three-staged, risk-based approach given in the Energy Institute (EI) guidelines is employed to identify fatigue critical locations on topside piping. EI guidelines provide guidance for various stages of the risk assessment. However, authors feel that the qualitative methodology employed during stage 1 for identifying fatigue critical system is cumbersome. The paper thus proposes an alternative methodology to prioritize inspection of Potential Fatigue Critical Locations (PFCLs) on topside piping based on the Composite Priority Weights (CPWs) obtained from Analytic Hierarchy Process (AHP). An illustrative case study is performed, within which the hierarchy tree structure is developed. Thereafter, the CPWs of piping locations in different units are obtained. Thereby, the locations with high CPWs are prioritized for the quantitative assessment during the stage 2 of the risk assessment.