This study validated the application of clinical engineering tools to improve cardio-defibrillator technical verification procedures under real conditions in the public health system. It was observed that many of the non-conformities detected can be prevented and corrected by implementing systematic routines, adequate technical documentation, and ongoing staff training. Of the non-conformities identified, 110 originated from the visual inspection process, 72 from the electrical safety process, and 21 from the performance process. The use of cause-and-effect diagrams facilitated the analysis of these non-conformities, identifying improvement opportunities at each stage, promoting traceability, and fostering a culture of continuous improvement. An optimization of electrical safety tests was suggested, reducing the number of repetitions without compromising metrological validity, which contributes to a more efficient and sustainable evaluation. Likewise, it was reaffirmed that the “Auto-test” available in these technologies is a useful tool, but it must be complemented with on-site procedures to guarantee adequate levels of safety and performance, since it can generate false positives. The relevance of simple and low-cost actions, such as careful cleaning of the cardio-defibrillator paddle contacts, which favor the correct execution of the Auto-test, was also highlighted. These actions, based on learning and training, have a significant positive impact on the reliability of functional control. These results reaffirm the need to implement technical verification laboratories that provide after-sales verification services for medical equipment in use, in order to strengthen technological safety in the healthcare system and contribute to the efficient and sustainable development of the sector.