Sensitivity of Network-Level BMS MR&R Policies to Variations in Cost,Transition Probability,and Discount Factor

A sensitivity analysis of the recommendations obtained from the maintenance, repair, and rehabilitation (MR&R) optimization model of the Pontis bridge management system (BMS) to changes in Wisconsin’s estimates of MR&R costs, transition probabilities, and discount factor is presented. The scope includes the MR&R actions for 25 bridge elements in Wisconsin. The analysis is based on scenarios of cost and transition probabilities that represent a range of low- to high-cost projects and slow to fast element deterioration. The potential cost savings per element from adopting special policies on extreme high- and low-cost projects were estimated. The analysis identified the MR&R actions that are sensitive to changes in cost or transition probability, the MR&R actions that are never recommended, and the cost and transition scenarios for which the optimal policy is to do nothing until failure. The optimal policies recommended by the BMS and the current practice at Wisconsin District 1 were compared. Recommendations for improving Wisconsin’s MR&R cost database are presented.