1. A method for supervising the sensitivity of a protection function in an electrical power system comprising a metering device for measuring values of a feature, said protection function being configured to initialize an action based on a test value and a threshold value for the feature, wherein said test value is either a measured value or a value derived from the said measured values, characterized in that, during the operation of the protection function, the method comprises repeatedly: calculating a mean value and a deviation of the test values, determining the probability of a false action based on the calculated mean value, the threshold value and the calculated deviation, and indicating that the sensitivity is too high when the probability of a false action exceeds a first limit value for the probability of a false action.