1. A tree discovery method, the method carried out by program code stored on non-transient computer-readable medium and executed by a processor, the method comprising: identifying in computer-readable medium a first node for a system under consideration, each node in the computer-readable medium representing a characteristic of a component; selecting at least a second node from the computer-readable medium for the first node, the at least second node selected from a non-exhaustive sampling of nodes as a child node of the first node contributing more to an impact on the system under consideration than any other child node of the first node; and discovering in the computer-readable medium at least one system tree for the system under consideration based on the first node and the at least second node.