The incorporation of the Phasor Measurement Units (PMU) allow the development of new tools, both for planning, failure analysis and operation in Power Systems (PS); as a result of that, it increases the safety and reliability of the operation of the electric network, and failure analysis engineering. In this way, theories that combine phasor measurements with the circuital laws of a PS, it has been developed, thus determining the stress level of specific areas. In this research, a methodology is developed for failure analysis and dispatch optimization, based on a grouping technique called k-means, which divides a PS into different control areas, it increases the level of stress between their areas, as a consequence, it could be determined, applying the concept of cut's angle. With the above, critical areas are identified, and it avoids contingencies stages.