A formulation of the problem for the renewal of the distribution networks is presented in this paper. This formulation treats the problem as a multiobjective mathematical programming problem, which is concerned with the attempt to improve each objective simultaneously. The objectives consist of three important terms: the economical cost, the environment impact and the reliability of the distribution networks. In this optimization problem, it is attempted to minimize the economical cost, environmental impact and to maximize reliability of the distribution networks. The suggested method is based on a dynamic model and heuristic solutions, by use of fuzzy-logic. Some hypothesis are considered in some stages of the process.
