1. A computer readable storage medium on which is embedded one or more computer programs, said one or more computer programs implementing a method for detecting events based upon attributes read by a plurality of entities, said one or more computer programs comprising computer code for: receiving data pertaining to the read attributes from the plurality of entities; performing a correlation analysis on the data to identify a number of independent variables existing among the read attributes for each of a plurality of groupings of the plurality of entities in a first hierarchical level of the plurality of hierarchical levels; comparing the identified number of independent variables with a nominal number of independent variables for each of the plurality of groupings in the first hierarchical level; and determining that an event has been detected in response to the identified number of independent variables falling outside of a predetermined value from the nominal number of independent variables for a particular grouping in the first hierarchical level.