A method and system of scheduling demands on a system having a plurality of resources are provided. The method includes the steps of, on receipt of a new demand for resources: determining the total resources required to complete said demand and a deadline for the completion of that demand; determining a plurality of alternative resource allocations which will allow completion of the demand before the deadline; for each of said alternative resource allocations, determining whether, based on allocations of resources to existing demands, said alternative resource allocation will result in a utilization of resources which is closer to an optimum utilization of said resources; and selecting, based on said determination, one of said alternative resource allocations to complete said demand so as to optimise utilization of resources of the system.