A method, performed by a Management System network node responsible of network management, for detecting outage of a radio cell served by a second network node, the Management System network node and the second network node operating in a wireless communications system, the method comprising: determining a number of incoming handovers for the radio cell of the second network node in a first measurement period, determining a number of incoming handovers for the radio cell of the second network node in a second measurement period, wherein the second measurement period is a previous measurement period to the first measurement period, and wherein the Management System network node determines that the radio cell is in outage when: the determined number of incoming handovers in the first measurement period is under or equal to a threshold, the determined number of incoming handovers in the second measurement period is higher than the threshold, and one of: a) one or more performance indicators in the first measurement period have not been provided by the second network node, or b) the one or more performance indicators in the first measurement period have been provided by the second network node, and the radio cell is not active in the first measurement period, or c) the one or more performance indicators in the first measurement period have been provided by the second network node, the radio cell is not active in the first measurement period, and the radio cell is not switched off in the first measurement period. determining a number of incoming handovers for the radio cell of the second network node in a first measurement period, determining a number of incoming handovers for the radio cell of the second network node in a second measurement period, wherein the second measurement period is a previous measurement period to the first measurement period, and wherein the Management System network node determines that the radio cell is in outage when: the determined number of incoming handovers in the first measurement period is under or equal to a threshold, the determined number of incoming handovers in the second measurement period is higher than the threshold, and one of: a) one or more performance indicators in the first measurement period have not been provided by the second network node, or b) the one or more performance indicators in the first measurement period have been provided by the second network node, and the radio cell is not active in the first measurement period, or c) the one or more performance indicators in the first measurement period have been provided by the second network node, the radio cell is not active in the first measurement period, and the radio cell is not switched off in the first measurement period. the determined number of incoming handovers in the first measurement period is under or equal to a threshold, the determined number of incoming handovers in the second measurement period is higher than the threshold, and one of: a) one or more performance indicators in the first measurement period have not been provided by the second network node, or b) the one or more performance indicators in the first measurement period have been provided by the second network node, and the radio cell is not active in the first measurement period, or c) the one or more performance indicators in the first measurement period have been provided by the second network node, the radio cell is not active in the first measurement period, and the radio cell is not switched off in the first measurement period. a) one or more performance indicators in the first measurement period have not been provided by the second network node, or b) the one or more performance indicators in the first measurement period have been provided by the second network node, and the radio cell is not active in the first measurement period, or c) the one or more performance indicators in the first measurement period have been provided by the second network node, the radio cell is not active in the first measurement period, and the radio cell is not switched off in the first measurement period.