1. An infrastructure management system comprising: a first server comprising a first processor, a first memory, and a first set of program instructions stored in the first memory; wherein the first processor, executing the first set of program instructions: determines a target configuration of a target set of virtual machines on a target set of hosts of a computing system, the target set of virtual machines and the target set of hosts having a plurality of resources associated therewith; for each of the plurality of resources, and based upon the target configuration: calculates a sum of available capacities of the target set of hosts; calculates a sum of Nth percentile resource consumptions for the target set of virtual machines; calculates an ideal headroom for the resource based upon the sum of available capacities and the sum of Nth percentile resource consumptions; determines a threshold score for the target configuration, based upon the calculated ideal headrooms; determines a placement of the target set of virtual machines on the target set of hosts, based upon the threshold score, wherein the placement comprises a set of virtual machine host pairs from the target set of hosts and the target set of virtual machines; and installs the target set of virtual machines on the target set of hosts, according to the placement.