Optimal inspection strategies for offshore structural systems

Optimal planning of inspection and maintenance strategies for structures has become a subject of increasing interest especially for offshore structures for which large costs are associated with structural failure, inspections and repairs. During the last five years a methodology has been formulated to perform optimal inspection and repair strategies for structural components subject to uncertain loading conditions and material behavior. In this paper this methodology is extended to include also system failure i.e. failure of a given sub set of all the structural components. This extension includes a mathematical framework for the estimation of the failure and repair costs associated with systems failure. Further a strategy for selecting the components to inspect based on decision tree analysis is suggested. Methods and analysis schemes are illustrated by a simple example.