Applying Semantic Rules to Achieve Dynamic Service Oriented Architectures

摘要

As the complexity and tempo of world events increase, Command and Control (C2) systems must move to a new paradigm that supports the ability to dynamically modify system behavior in complex, changing environments. Historically, the behavior of Department of Defense (DoD) C2 systems has been embedded in executable code, providing static functionality that is difficult to change. We propose the use of semantic models to represent system behaviors abstracted from procedural code, and we demonstrate that this provides a well-defined foundation for dynamic Service Oriented Architectures. This paper describes an implementation that models a military convoy traveling through an unsecured area under changing conditions. The W3C standard Web Ontology Language (OWL) was used to describe the battlespace domain, and the proposed W3C Semantic Web Rule Language (SWRL) was used to capture recommended operating procedures for convoys in theater. In our experiment, two sets of rules were used: one set models rules of engagement for favorable visibility conditions on the battlefield, and the other models rules of engagement for poor visibility conditions. Ontologies and rule sets were translated into integrated knowledge bases that could be consulted as a service to derive alerts and recommendations for the convoy commander. Messages injected over an enterprise service bus (ESB) provide the changing conditions that affect the battlespace. We then were able to show that a dynamic event, such as an unexpected sandstorm, causes the appropriate set of rules of engagement grounded in the ontologies to be applied to the service to guide the convoy to safety. This paper describes the overall approach and the challenges we encountered. We outline the architectural options for constructing dynamic services and describe the semantic-based approach selected. We conclude with our findings and recommendations, including a set of requirements for a standard rule language needed to support agile services.