1. A method of identifying a set of pre-provisioned machine configurations and an associated mapping function for mapping each of a plurality of given machine configurations to said set of pre-provisioned machine configurations so as to produce a resource cost for said set of pre-provisioned machine configurations, the method comprising the steps of: clustering said plurality of given machine configurations into a quantity of clusters less than or equal to a pre-specified amount; determining a respective dominant provisioning machine configuration for each cluster of said quantity of clusters; and determining an overall over-provisioning resource cost associated with the respective quantity of clusters and associated respective dominant provisioning machine configurations; and assigning to said mapping function the respective associated dominant provisioning machine configuration of each respective cluster of said quantity of clusters as the target for the given machine configurations of each respective cluster of said quantity of clusters.