Multi-objective Maintenance Optimization of Aging Bridge Decks

As discussed earlier, the actual maintenance optimization problem is multi-objective in nature as the bridge owner or manager seeks to satisfy simultaneously several objectives, such as the minimization of maintenance costs, improvement of safety, serviceability and functionality, minimization of maintenance time, minimization of traffic disruption, minimization of user costs, and minimization of risk of failure, etc. The solution of this maintenance management problem can be obtained using the techniques of multi-criteria or multi-objective optimization. Several approaches have been developed to solve multi-objective optimization problems, including multi-attribute utility theory (Von Neumann and Morgenstern 1947; Keeney and Raiffa 1976), weighted sum approach (Zadeh 1963), compromise programming, constraint approach, and sequential optimization (Koski 1984; Duckstein 1984; Lounis et al. 1993, 2000). In this paper, the compromise programming approach is used to solve the multi­objective maintenance optimization problem, and is presented in the next section.