ReFFlow – Web Service Reusable Flexible Flows

Web services are technology addressing system and application integration over the Web and across organizational boundaries.
Web services (WSs) are an incarnation of the service-oriented architecture (SOA) and comply with its main principles:

• separation of service description and implementation
• dynamic discovery of business logic - WSs are registered in (UDDI) registries and discovered
• composability - simple WSs can be combined in complex WSs

Web services expose any kind of functionality via a standard interface. The interfaces are described in WSDL - an XML language describing services in terms of the messages they consume and produce. WSs are accessible over the Web using standard access mechanisms. The interaction among WSs is message based and therefore loose-coupling is ensured. To the users Web Services are platform, programming language and protocol independent - i.e. all user can access a Web Service through a standard unified interface.

The technology's development has great progress, mainly because of industry acceptance. However, the technology is still immature. The insufficiently supported or missing features include:

• ability to compose simple Web services in complex ones and use them for complex business applications,
• transactional support for interactions among Web services,
• coordination protocols
• security

The ReFFlow project focuses on creating an extended meta-model for Web Service based processes, called also WS compositions, Web Service Flows, or WS-flows shortly. The ultimate goal is to develop an infrastructure for development and execution of WS-flows based on the extended meta-model. The extensions of the meta-model aim at providing adaptability of processes at run time.
WS-flows adaptability can be ensured if the following are made possible: WS instance swapping, change in service type and process logic (control and data flow). Additionally, adaptability is facilitated by involving WS instance selection policies, based on quality of service criteria and user-defined criteria.
Additional goal of the ReFFlow infrastructure is to ensure the automatic creation of WS-flow definitions based on the principle of code and functionality reuse. Automating the creation of WS-flow definitions is made easier by the use of activity and process templates.

ReFFlow Infrastructure

The ReFFlow infrastructure has three major components:

• Process Engine - executes the WS-flows
• WS-flow Editor - used to create and edit WS-flow definitions; supports meta-model extensions for adaptability
• Instance Browser - monitors and controls the running WS-flow instances

ReFFlow News

Team

Prof. Alejandro Buchmann, Ph.D.
Dimka Karastoyanova
Mariano Cilia
Alejandro Houspanossian

For further information contact Dimka Karastoyanova.