Enhancing a BPEL4WS Engine

This work provides an implementation of the ReFFlow model for adaptable WS-flows. This implementation is incorporated into a BPEL-compliant engine. The resulting system supports the execution of WS-flows defined with an enhanced BPEL language (i.e. built-in support for the ReFFlow model). In this work we combine Open-Source Software (OSS) with Aspect-Oriented Programming (AOP). Basically, we apply AOP to extend an evolving open-source system (the base system). By adopting AOP, we add new behavior to the base system without modifying its source code. This approach has shown to be highly maintainable. Our extensions (developed as aspects of the base system) have been successfully applied to different versions of the open-source system. In this way, we address one of the major drawbacks related to the adoption and extension of OSS (i.e. managing OSS’s evolution).