The use of random variables and the application of probabilistic techniques for power system analysis has become an important issue due to the increased uncertainties faced by modern power systems. In the techno-economic analysis of an installation, especially at the design stage, several discrete values have to be considered for each variable, such as voltage, power, power angle, etc. Therefore, in handling such problems, it is advisable to use random variable ranges as explained in the paper taking the area of power transmission engineering as an example.
