A unified algorithm to automatic semantic composition using multilevel workflow orchestration

As a result of state-of-the-art development in service oriented architecture, we need a composition framework and comprehensive algorithm to discover and compose the web services from different environments. In this paper, we present a unified semantic-oriented framework with corresponding algorithm for automatic web service composition that integrates the comprehensive process of modified multistage composition and rigor of web semantics. Our proposed unified algorithm introduces the novel features through modified five stage composition such as transformation of non-functional properties of user requirements to all stages, optimization and semantic validation of abstract workflows using workflow automata, annotating WSDL files with additional ontologies using ontology based service repository, adopting dynamic change of user requirements for discovering candidate services, and selecting most optimal services for concrete composition using non-functional properties are effectively represented. Feasible composition solution obtained for user complex requirements through semantic web service discovery mechanism for discovering and selecting the most suitable service candidates. Furthermore, our unified algorithm can provide a composition solution through wider acceptance of semantics-oriented documents such as web ontology language for services and web service modeling ontology. We evaluate the proposed unified algorithm for automatic generation of composition using our motivating scenario, namely, home loan approval inference process. We also evaluate algorithm for automated and dynamic composition on service repositories of various sizes in increasing the levels of nesting and present the performance results.