This paper presents a comparison of the necessary grid reinforcements of a distribution grid by considering the approaches for application of different performance indices. The aim is to enable an optimal integration of renewable energies sources into the existing grid structure and to utilize the grid in the best possible way. In addition, the necessary grid reinforcements should be targeted to be as low as possible. For this purpose, the required grid expansion will be estimated by applying the grid planning method, which will be presented in this paper, under application of the performance indices. These performance indices can be determined from the results of the contingency analysis in order to evaluate the impact of line outage on the other lines. This enables a targeted identification of grid reinforcements and expansion measures using the developed method in the time-series-based probabilistic grid planning.