1. A system comprising: a plurality of security sensors distributed throughout a plurality of sites, each sensor configured to generate a sensor signal in response to a defined event, wherein the sensor signal is provided in a native format proprietary to a manufacturer of the respective sensor; a central security management processor coupled to the plurality of security sensors, configured to receive sensor signals from each of the plurality of security sensors and configured to manage individual user profiles and their respective access privileges and credentials in the system; a normalization module configured to normalize the sensor signal data in accordance with a defined data mapping scheme by mapping the sensor signal data from each security sensor in the native format of each manufacturer to a common format, the common format including a data object and processing information for the sensor signal, the normalization module further configured to generate unique physical access privileges and credentials to exclusively map a user's profile to a spatial hierarchy of physical sites along with security devices of the system, wherein the unique physical access credentials maintain a common representation of the user's identity across the plurality of sites and to associate specific user identities with respective actionable events; a visual policy manager having a rules definition component configured to define, at design time, physical security policies in the context of user profiles at all sites through actionable representations of physical, network and information technology resources of the sites, wherein the security policies define standardized rule definitions through visual rules depicted by live objects that contain attributes to define their spatial relationship to the actionable representations, and that are applied to the actionable events normalized to the common format to produce normalized event data; and a signal processing component applying, at run time, the defined standardized rules comprising condition-action sequences including relevant transformation and routing rules to the normalized signal data and to invoke the defined responses to the actionable events in order to maintain user profiles and physical security states across the plurality of sites and to resolve the actionable events through the associated specific user identities.