There is described a method of managing network slices in a communications network. The method comprises a domain manager of a Radio Access Network (RAN) determining a change in cell composition of the RAN, and determining neighbor cells within the RAN affected by the change in cell composition of the RAN. The method also compromises the domain manager determining a set of RAN resource partitions affected by the change in cell composition of the RAN, and adapting the configuration of RAN resource partitions of the set of RAN resource partitions by introducing changes corresponding to the change in cell composition of the RAN.