Hospitals, thanks to a constant evolution of health technology, have the task to improve reliability of services and to preserve patients and workers from malfunctions, both mechanical and human. To this aim, recently, reliability tools have started to be adopted in the health field. In its constant pursuit for a better health service, in 2012 the Technology Assessment structure at the Azienda Ospedaliero-Universitaria of Trieste started an interdisciplinary activity of verification of malfunctions occurring in the dialysis and nephrology unit.