A simplified method for holistic value of information computation for informed structural integrity management under uncertainty

Abstract Collecting structural information by inspection or monitoring is important means to reduce uncertainty and improve the qualities of maintenance decisions in structural integrity management. However, information collecting inevitably involves some costs. When information collecting brings added value and to what extent uncertainty reduction suffices are questions that are often not fully accounted for before information collecting activities are carried out. Value of information (VoI) computation helps justifying investments and informing efficient strategies for information collecting. This paper develops a holistic approach to quantify the VoI from multiple inspections in the lifetime of an engineering structure, taking into account combined effects of lifetime maintenance interventions. The approach can be used for holistic planning and optimization of lifetime inspections at an early stage. Also, a simplified VoI computation approach is developed for some maintenance decision cases based on an alignment decision strategy (ADS). The approaches are exemplified on a typical marine structure, and sensitivities of VoI to the number of planned interventions, cost ratio, inspection times and methods are studied. It is shown that the ADS and the simplified method are well applicable when the number of planned interventions is large. The optimal maintenance decisions and inspection times obtained by VoI-based and cost-based optimization methods are compared.