The physical guarantee of a power generation plant corresponds to the minimum amount of energy that the plant can guarantee in an unfavorable scenario of inflows, based on historical data. It is, therefore, the amount of energy that the plant can commit in its sales contracts or self-consumption. The rules of the Brazilian electricity market allow a seasonal distribution of the physical guarantee of each plant. Seasonalization process consists in converting the average annual values of the plant physical guarantee into monthly values. The generator must declare the seasonalization of the physical guarantee annually, in December, at the Electric Energy Commercialization Chamber (CCEE). The decision on how to realize the seasonalization over the following year is made in an uncertain environment, as it depends on unknown initial data, such as future energy prices and the allocations of the Energy Reallocation Mechanism (MRE). This work proposes a strategy for seasonalization of the physical guarantee of a set of power generation plants based on models of multicriteria decision-making under information uncertainty

Keywords : Energy seasonalization, multicriteria decision making, uncertainty factor, robust solutions, general decision making scheme.