A communication system (200) comprises a system management function (246) for managing base-site resources and system throughput of data. The system management function (246) defines a number of resources. The system management function (236), such as a radio network controller, comprises a data throughput identification function to identify one or more bottleneck resources from a sub-set of system resources involved in the system's data throughput. A method of reducing power consumption (MIPS) in a system management function (236) and a radio network controller (236) are also provided.The identification of a bottleneck resource helps determine whether MIPS could be saved by not performing one or more QoS management algorithms, the benefit from which is reduced due to the bottleneck resource.