An approach to semantic re-composition of Web services for service-oriented architecture

Service oriented architecture (SOA) is a newly emerged and future method based on the Web services and SOAP for IT development in a distributed environment. As a state-of-art architecture, its concrete details are absent by its nature. This paper is intended to provide a mechanism for an IT system to dynamically adapt itself to business application logic at the system runtime, that is, a mechanism for automation of the orchestration layer in SOA. The idea is to introduce First-order Logic (FOL), a formal logic applied in many areas, e.g. mathematics, computer science and philosophy, etc., to facilitate the layer's responsibility to understand changes of business application processes and modify the layer's business logic of its Web services accordingly. Each logic rule of business application processes becomes a FOL sentence the orchestration layer read it and interprets the semantics of the sentence into its Web services that are needed. This becomes possible because the business Web services as well as the data services of SOA are built on the basis of XML data that is semi-structured and can easily be organized to form a FOL sentence. Thus, with the interference ability of the FOL, the system of SOA can dynamically reconfigure its services to meet the requirement of its business customers.