Sustainable decisions for maintenance and protection of important infrastructure require both the life-cycle assessment of performance, and the comparison between investments for safety and the benefits of keeping the safety level within acceptable margins. Given the large amounts expended to build infrastructure, it is convenient to develop approaches to measure the economical efficiency of alternative strategies, aimed at maintaining the service and capacity of the infrastructure facilities to generate income. In this chapter, a closer and new look at the old problem of how safe is safe enough, is provided.