This paper describes a system that supports the specification of a large set of simulations and their organization and distributes execution over a PC's network under Windows 95 and NT. Our objective is two faced: maximize resources utilization of IBERDROLA and the possibility of starting experiments that require a high compute power. As an example, we will describe the work done in the ESPRIT project 27238, PHASE, where the total number of analysis increases exponentially, and the maximum resources are required to obtain reasonable order of response time. PHASE is an integrated tool, user oriented, to automatically define, execute and analysis of hundreds of required simulations for a valid study and future electric network planning.