1. A computer-implemented method for provisioning a virtual machine onto shared physical resources, the method comprising: identifying a set of workload characteristics for a candidate mix of virtual machines; determining a probability that an aggregate resource utilization by the virtual machine and the candidate mix of virtual machines exceeds a predefined set threshold for resource utilization over a time horizon, wherein the step of determining the probability that the aggregate resource utilization by the candidate mix of virtual machines exceeds the predefined set threshold for resource utilization over the time horizon further comprises: creating a profile of a set of time samples for the aggregate resource utilization by the candidate mix; determining a sample mean and sample standard deviation from the created profile; setting the predefined set threshold to a one-sided upper tolerance limit of the created profile; determining a coverage factor for the created profile; and determining an upper bound on the probability of exceeding the set threshold; and provisioning the virtual machine along with the candidate mix of virtual machines to a physical machine.