Model-driven design, simulation and implementation of service compositions in COSMO

The success of software development projects to a large extent depends on the quality of the models that are produced in the development process, which in turn depends on the conceptual and practical support that is available for modelling, design and analysis. This paper focuses on model-driven support for service-oriented software development. In particular, it addresses how services and compositions of services can be designed, simulated and implemented. The support presented is part of a larger framework, called COSMO (COnceptual Service MOdelling). Whereas in previous work we reported on the conceptual support provided by COSMO, in this paper we proceed with a discussion of the practical support that has been developed. We show how reference models (model types) and guidelines (design steps) can be iteratively applied to design service compositions at a platform independent level and discuss what tool support is available for the design and analysis during this phase. Next, we present some techniques to transform a platform independent service composition model to an implementation in terms of BPEL and WSDL. We use the mediation scenario of the SWS challenge (concerning the establishment of a purchase order between two companies) to illustrate our application of the COSMO framework

Model Transformation from OWL-S to BPEL via SiTra

Although there are a large number of academic and industrial model transformation frameworks available, allowing specification, implementation, maintenance and documentation of model transformations which provide a rich set of functionalities, such tools are inherently complex. In particular, for a newcomer to the field of model transformation and for researchers who are only interested in experimentation and creation of prototypes, the steep learning curve is a significant hurdle. There is thus a clear scope for the creation of model transformation frameworks that are both easy to use and able to conduct complex transformations. Simple Transformer (SiTra) is a model transformation framework, which was originally designed to be a "way in" for the experienced programmer, to start using the concepts of model transformation, and for academic researchers to experiment with the creation of prototypes of implementation of their transformations. The underlying idea of SiTra is to put less focus on the specification language, maintenance and documentation aspects of transformation, by focusing on the implementation of transformations. SiTra makes use of Java for the specification of transformations. This alleviates the need to learn a new specification language or get to grips with a new tool and development environment. SiTra is equipped with a strong transformation engine to execute the transformation behind the scenes. This paper reports on a case study involving transformations from Ontology Web Language-Service (OWL-S) to Business Process Execution Language (BPEL), demonstrating that SiTra can also be used to handle complex and large transformations

SYMEX: A Systems Theory based Framework for Workflow Modelling and Execution

Workflow management systems enable organisations to deal with all aspects of business process management, including analysis, modelling, execution, and administration. Modelling workflow processes involves transformation of the process logic into a formal representation and it always remains a critical success factor for these systems. Workflow modelling languages provide constructs for capturing high-level descriptions of business processes, which are then have to be transformed and encoded into low-level execution semantics with the use of workflow programming languages. However, maintaining these models separately results in a number of issues, particularly when the various interdependencies between them are managed manually. This primarily creates difficulties in adaptation, in terms of identifying changes in high-level descriptions due to modifications of business conditions, and tracing the impact of those changes on the low-level execution semantics. Moreover, certain information included in the high-level descriptions is either partly encoded or omitted from the low-level execution semantics and at the same time, complicated business rules encoded at the execution level are not included in the high-level descriptions, creating major inconsistencies. The above issues result in high maintenance costs, reducing the overall efficiency and performance of workflow management systems. This thesis addresses the aforementioned problems by proposing a framework named SYMEX. SYMEX addresses the issue of integrating high and low-level descriptions in one unified format, from a Systems Theory perspective. SYMEX models have a mathematically defined formalism capable of capturing both high-level descriptions of business processes and low-level workflow execution semantics. Furthermore, SYMEX offers a concise and easy to learn and communicate set of constructs, allowing business analysts, process designers, and programmers to work on the same model, at different levels of abstraction. Apart from the theoretical framework, an XMLbased approach for the application of SYMEX is proposed, along with a constraint- based inference engine. Additionally, SYMEX models are evaluated in terms of their complexity and prove easier to read, understand, and manage than other traditional workflow modelling approaches. However, further research is required to assess the capability of the framework, with respect to modelling workflow processes in a service-oriented environment, where activities of business processes are essentially web-services exposed on the Internet