No monitoring system is perfect, and real-life situations often involve unexpected changes, such as sensor malfunctions, maintenance needs or environmental shifts. The UnderSec study includes scenarios that explore what happens when a sensor fails within the network and how this affects the overall ability to detect new transmitters. These examples show that some failures can have a strong impact on coverage, especially in areas where the network is already under pressure. 

In the simulations, when one sensor is removed from the network, the area that remains well covered by at least three sensors shrinks considerably. On the interactive map, this change is immediately visible: regions that had been highlighted as strongly protected become smaller, and new blind or weakly covered zones appear. This makes the consequences of a failure easy to understand at a glance, without requiring users to interpret technical logs or numerical tables. 

Such information is highly valuable for resilience planning. Operators can identify which sensors are critical and where redundancy is needed, plan backup solutions, and prioritise maintenance or upgrades in the most sensitive locations. By showing how the system reacts to failures and configuration changes, the UnderSec tool helps build monitoring networks that can better withstand disruptions and continue to protect people and infrastructures over time.