1. In a service network having components interconnected by segments for providing services to end users, a method of reporting network health comprising: defining a hierarchical tree structure indicative of a policy aggregation tree, the tree having branches and a hierarchy of levels, each branch including sub-trees in a parent/child arrangement, wherein each higher level in the hierarchy corresponds to an aggregation of attributes such that lower child levels impart status to higher parent levels closer to a root of the tree, the aggregation defining branches including a sub-tree of attributes; receiving a request for a report of network health, the request designating one or more attributes, wherein at least one of the one or more designated attributes is a metric category attribute, or a metric attribute; filtering, by computer, the tree structure according to a reporting criteria included in the request by pruning branches of the tree structure to include branches of the tree corresponding to status values of attributes that are requested for reporting, and to omit branches of the tree corresponding to unrequested status values, wherein filtering designates vertical subdivisions through the hierarchy, the vertical subdivision omitting the attributes of the pruned branches and including attributes of requested attributes; and aggregating the status values by including, based on a summation of the status values in the included branches, attributes of the filtered tree structure, wherein child attributes affecting a parent status value at a successive level of the filtered tree are included, and wherein status values in pruned branches are omitted.