The energy networks’ performance depends on the architecture of the network as well as on the energetic transfer command. From the fact of the complexity of this architecture which involves the energy network from many diverse resources of different natures ( production units, transformation stations, transport lines, consumption modes…), the auxiliary network (communication network, protection plan, signalisation and observation network,…) and the human network (including all the levels contributes going from dispatching down to un-keep and maintenance), it’s necessary to proceed to the situation’s global analysis by adopting a causal process including the different steps that could proceed any disturbance. It’s also necessary to analyse the incident’s dynamics, by exploiting the systematic method of Interventions’ Planning Per Objectives (PIPO), this causal analysis allows us to put into evidence the tree of problems illustrating the causes of high voltage electrical systems’ collapses. This tree constitutes a precious tool able to stop the intervention strategy in order to either avoid the black out or at least to reduce it on a given exploitation horizon. In the case of the back out occur and in seen to control the refeeding of the customers, a restoration’s plan of the network must be established beforehand.