The aim of this thesis is to verify the selectivity analysis for Tunadal supply system and to compare which software analyze tool is most suitable for SCA's future projects. A correctly issued selectivity analysis allows only protection closest to the faulty field to trip. A faulty selectivity analysis may instead cause the parts of the network that are not really affected by the fault to trip. The survey was conducted by collecting data on the components used to calculate the over- current and short-circuit current. These data will later beused as the setting value of relay protection. The calculated values are then used in the software to simulate the selective plan. The results shows that the current values of relay protection settings can be adjusted to achieve greater safety and durability of large part of the components. The software is being compared by the questions given by SCA, and also from own experiences. The choice of using Netkoll and Neplan as software analyze tool is because the two handles selective analysis for high supply system, and also because the software is in differprice range.