Integrated Life-cycle Decision Framework for Structural Systems

A large part of the investment in public infrastructure is dedicated to designing and constructing the infrastructure and to mitigating deterioration processes, such as corrosion and fatigue damage. In practice, the different phases of a structure's life-cycle are managed by different teams with little interaction. Unfortunately, the optimization of the individual phases does not necessarily result in an optimal life-cycle cost. This motivates the development of models and procedures that treat structural optimization from a broader life-cycle perspective. This paper discusses the possibility to enhance the design of structural systems by reflecting the operation and maintenance phase in the design decision framework. The inter-dependency between decisions made at different points during the life-cycle is accounted for by means of a sequential decision analysis. A hi-erarchical influence diagram is proposed as an efficient way to model the probabilistic decision framework while considering system effects, such as the spatial correlation of the deterioration mechanisms. Challenges in the implementation of the framework are documented and potential applications are discussed. A simple example is presented to assess the performance of the model.