ABSTRACT
In the second section we present the two survival models we have applied: the Cox Proportional Hazard model and the Generalized Linear models. We also introduce Receiver Operating Characteristics (ROC) graph as a way to evaluate concordance between models and real data. The third section is devoted to describing data from the water supply company of a medium-sized Spanish city. In the second and third subsections we apply the different models to these estimations, commenting on their advantages and disadvantages, as well as on their suitability in the failure
risk analysis in question. In the fourth subsection the different fits are compared by means of the ROC curves. Finally, we will come to some conclusions in which we try to asses their validity not only for this case but also, to some extent, to any other WSS.
