Remote diagnosis of electrical distribution networks contributes greatly to their global performance, obviously on technical grounds, but also on 3 economic factors: 1) the reduction of technical losses through a detailed knowledge of all energy flows at various nodes of the network; 2) the optimization of investments and of operational costs through precise information on the network status and its operation conditions and 3) the improvement of the energy dependability (availability and quality) through close monitoring of the energy delivery conditions and the identification of the possible need for correction and their most efficient locations. There is a fourth economic factor, relevant for distribution companies: the reduction of total losses through the reduction of the non-technical losses. This paper demonstrates for the first time a method to calculate and locate on-line the non-technical losses in a distribution system. All these factors largely justify the implementation of a DMS system including a corporate IT platform to feed data from the GIS (or other information systems, NIS, etc.) on a central data base repository and the means to capture and maintain the model data.