Formally Modeling and Analyzing the Reliability of Composite Service Evolution

Service composition is an important means for integrating the individual Web services for creating new value added systems. However, Web service exists in the heterogeneous environments on the Internet, thus it is challenging to guarantee the reliability of composite service evolution. To address this problem, we propose the approach to modeling and analyzing the reliability of composite service evolution. First, we present a formal description language to model the different components of service composition, and use it to analyze the reliability of composite service evolution. Second, we propose an evolution mechanism to ensure that service composition can dynamically meet the required reliability. Third, we present the operational semantics and related theories of Petri nets for establishing the consistency in the evolution process. We have also performed a series of simulations to evaluate our proposed method. Results show that it can help reveal the structural and behavioral characteristics of service composition, and improve the reliability of composite service evolution.