Software components composition can improve the efficiency of knowledge management by composing individual components together for complex distributed application. There are two main areas of research in knowledge representation for component composition: the syntactic based approach and the semantic-based approach. In this paper, the authors propose an integrated ontology-supported software component composition. The authors’ approach provides dual modes to perform component composition. Ontologies are employed to enrich semantics at both components description and composition. The authors demonstrate that their search engine SEC++ fulfills automated component composition, in particular, and knowledge management in general.
TopComponent composition is to construct higher-level components based on existing multiple individual ones in order to fulfill more sophisticated business requirements. An example of components composition is generating a comprehensive conference travel plan, including conference registration, flight ticket booking, hotel reservation, car rental, map request, and so forth, from existing components. Depending on whether a composition decision is made at design time or at run-time, it falls into either static or dynamic composition, respectively (Cardoso, Busslerand, Shethand, & Fensel, 2002). From a process standpoint, component composition can be done horizontally, vertically, or both. The aforementioned example belongs to vertical composition, because hotel booking cannot be carried out until the flight ticket is issued. However, car rental and map request can be performed simultaneously in a horizontal way. Component composition poses challenges from the following multiple aspects along the composition course (Cardoso et al., 2002): (1) description or representation of components; (2) components discovery; (3) integration of individual components; (4) QoS-based optimization of component composition as well as other issues.
The syntactic-based component composition approach already has been used widely in the industry (Agarwal, Chafle, Mittal, & Srivastava, 2008). Although more vocabularies are added for component description, messaging, those constructs are still concerned mainly with document structure or syntax. The component discovery, matching, and integration utilize keyword searching, which has been usually proved ineffective by information retrieval researchers.
The semantic-based component composition addresses the semantics-absent problem of the syntactic-based approach. In the component composition context, the RDF+OWL technology can help component description, advertisement, discovery, integration, interoperation, invocation, execution, and monitoring, which all converge at component composition (Cardoso et al., 2002). In the context of component composition, ontologies can be employed to distill all concerned concepts in a certain domain as a centralized repository, which shows superiority for on-the-fly component choreography by specifying semantic relationships between component terms.