A method for optimizing a self organizing network comprising a plurality of cells. The method comprises monitoring performance measurement data indicative of performance of one or more cells in a group of cells in the network, and monitoring trace data indicative of traffic statistics within the cells of the group. The method comprises generating, from the performance management data and the trace data, a plurality of key performance indicators each indicative of performance of an aspect of a cell in the group, and processing the key performance indicators so as to generate a hotspot value indicative of general performance of the cell in the group. The method comprises comparing the hotspot value with a threshold hotspot value, and if the hotspot value is greater than the threshold hotspot value, processing attribute data from the cells in the group so as to generate cause data indicative of a cause associated with the hotspot value exceeding the hotspot threshold value. The method also comprises generating, from the cause data, recommendation data for modifying an attribute of the network, and modifying the attribute of the network based on the recommendation data.