The electrical systems are subjected constantly to failures caused by nature (lightning, fires, windstorms, rain, frost, etc.) or by human actions (design, operation and communication mistakes and vandalism) and to intrinsic failures of the own equipment that compose them. As the type of disorder, can happen single or multiple contingencies.

The systems are planned by the N-1 reliability criterion, which means that they must be able to withstand any single contingency without interrupting the supply. However, in real-time, operations are subject to contingencies involving the loss of two or more components. ONS has been working continuously in order to add extra security to the BIPS performance through various initiatives.

In order to minimize the chances of any major disturbance, restricting the spread of a disorder and streamline the recovery of charges it is necessary to maintain a permanent work of observation, analysis, diagnosis and prevention of these events.