Remco M. Dijkman

Service-oriented Design: A Multi-viewpoint Approach

As the technology associated with the Web Services trend gains significant adoption, the need for a corresponding design approach becomes increasingly important. This paper introduces a foundational model for designing (composite) services. The innovation of this model lies in the identification of four interrelated viewpoints (interface behaviour, provider behaviour, choreography, and orchestration) and their formalization from a control-flow perspective in terms of Petri nets. By formally capturing the interrelationships between these viewpoints, the proposal enables the static verification of the consistency of composite services designed in a cooperative and incremental manner. A proof-of-concept simulation and verification tool has been developed to test the possibilities of the proposed model.

Methodological support for service-oriented design with ISDL

Currently, service-oriented computing is mainly technology-driven. Most developments focus on the technology that enables enterprises to describe, publish and compose application services, and to communicate with applications of other enterprises according to their service descriptions. In this paper, we argue that this technology should be complented with modelling languages, design methods and techniques supporting <i>service-oriented design</i>. We consider service-oriented design as the process of designing application support for business processes, using the service-oriented paradigm. We assume that service-oriented computing technology is used to implent application support. The paper presents two main contributions to the area of service-oriented design. First, a systatic service-oriented design approach is presented, identifying generic design milestones and a method for assessing the conformance between application designs at related abstraction levels. Second, a conceptual model for service-oriented design is presented that provides a common and precise understanding of the terminology used in service-oriented design. The ISDL modelling language is introduced to express service-oriented designs, based on this conceptual model. The paper includes an elaborate example to illustrate our ideas.

An approach to relate viewpoints and modeling languages

The architectural design of distributed enterprise applications from the viewpoints of different stakeholders has been proposed for some time, for example, as part of RM-ODP and IEEE 1471, and seems now-a-days to gain acceptance in practice. However, much work remains to be done on the relationships between different viewpoints. Failing to relate viewpoints may lead to a collection of viewpoint models that is inconsistent, and may therefore lead to an incorrect implementation. This paper defines an approach that helps designers to relate different viewpoints to each other. Thereby, it helps to enforce the consistency of the overall design. The results of this paper are expected to be particularly interesting for Model Driven Architecture (MDA) projects, since the proposed models can be used for the explicit definition of the models and relationships between models in an MDA trajectory.

Extending profiles with stereotypes for composite concepts

This paper proposes an extension of the UML 2.0 profiling mechanism. This extension facilitates a language designer to introduce composite concepts as separate conceptual and notational elements in a modelling language. Composite concepts are compositions of existing concepts. To facilitate the introduction of composite concepts, the notion of stereotype is extended. This extension defines how a composite concept can be specified and added to a languages metamodel, without modifying the existing metamodel. From the definition of the stereotype, rules can be derived for transforming a language element that represents a composite concept into a composition of language elements that represent the concepts that constitute the composite. Such a transformation facilitates tool developers to introduce tool support for composite concepts, e.g., by re-using existing tools that support the constituent concepts. To illustrate our ideas, example definitions of stereotypes and transformations for composite concepts are presented.