A computer implemented method of allocating a set of communications network resources to resource consumers in a digital communications system, the method comprising: generating a set of multiple allocation schemes each encoding the set of resources such that each resource is associated with a set of resource consumers, wherein each allocation scheme has associated a fitness measure evaluated based on the encoded set of resources and consumers in the scheme; iteratively applying a genetic algorithm to the set of allocation schemes to generate, at each iteration, a new set of allocation schemes as a generation of allocation schemes based on a preceding generation such that each allocation scheme in at least a subset of the allocation schemes in a generation is generated based on selected pairs of allocation schemes in a preceding generation, wherein the pairs of allocation schemes are selected by ranking the allocation schemes in the preceding generation based on the fitness measures, wherein each resource in each allocation scheme has associated an adjustable metric indicative of an age of an association between the resource and resource consumers in the allocation scheme, and the allocation scheme has associated a derived metric calculated based on the adjustable metric for each resource in the allocation scheme, wherein the ranking of the allocation schemes is based on the fitness measures of the allocation schemes weighted by the derived metric for the allocation schemes, and wherein the method further comprises: responsive to a predetermined stopping condition for the iteration, assigning resource consumers to resources in the communications system in accordance with an allocation scheme in a most recent generation determined to satisfy a ranking condition. generating a set of multiple allocation schemes each encoding the set of resources such that each resource is associated with a set of resource consumers, wherein each allocation scheme has associated a fitness measure evaluated based on the encoded set of resources and consumers in the scheme; iteratively applying a genetic algorithm to the set of allocation schemes to generate, at each iteration, a new set of allocation schemes as a generation of allocation schemes based on a preceding generation such that each allocation scheme in at least a subset of the allocation schemes in a generation is generated based on selected pairs of allocation schemes in a preceding generation, wherein the pairs of allocation schemes are selected by ranking the allocation schemes in the preceding generation based on the fitness measures, wherein each resource in each allocation scheme has associated an adjustable metric indicative of an age of an association between the resource and resource consumers in the allocation scheme, and the allocation scheme has associated a derived metric calculated based on the adjustable metric for each resource in the allocation scheme, wherein the ranking of the allocation schemes is based on the fitness measures of the allocation schemes weighted by the derived metric for the allocation schemes, and wherein the method further comprises: responsive to a predetermined stopping condition for the iteration, assigning resource consumers to resources in the communications system in accordance with an allocation scheme in a most recent generation determined to satisfy a ranking condition.