Annotations Governance and Validity Control mechanism (AGVC)
The purpose of the Annotations Governance and Validity Control (AGVC) mechanism is to deliver the following main kinds of functionality:
- Determination of policy well-formedness.
- Policy lifecycle management.
- Evaluation of policy validity.
With respect to the first functionality, the AGVC mechanism enables the articulation of constraints that impose structural restrictions on policies – i.e. they restrict those attributes that must (or must not) appear in a well-formed policy, as well as restrictions on the actual values (or value ranges) that the involved policy attributes may assume. These constraints are formulated in terms of a generic OWL 2 ontology, the Higher-level Ontology (HLO). With respect to the second functionality, the lifecycle of the policies is managed on the basis of a rule-set that is captured in terms of an ontology which constrains those subjects that are allowed to create, update or delete policies and the contextual conditions under which these operations may be performed. Finally, with respect to the third functionality, the AGVC mechanism assesses the validity of a newly-created (or updated) policy on the basis of its potential relations with other, already defined, policies. A policy that is found to be contradicting with one or more existing policies, or one which is subsumed by an existing policy, is deemed invalid.
The AGVC mechanism