Catálogo de publicaciones - libros

Business services are deliveries of capabilities to consumers. The way such capabilities are selected, combined and delivered makes for the flexibility in services provision compared to, for example, manufacturing of tangible goods. The coordination (‘orchestration’) of services is an essential requirement for the delivery of more complex services. However, current technologies for web service orchestration assume a procedural ‘program-like’ approach that as we argue in this paper reduces the flexibility to adapt the composite service in response to changing requirements. This paper proposes that service orchestration should be carried out at the business level, preserving the business semantics and transformed if required to specific orchestration execution models such as BPEL4WS, using MDA techniques.

Automated service composition is an important approach to create aggregate services out of existing services. Several different approaches towards automated service composition exist. They differ not only in the used algorithms but also in provided functionality. While some support the creation of compositions with alternative or parallel control flow, others are missing this functionality. This diversity yields from a missing consensus on the required functionality to automatically compose real-world services. Hence, with this paper we aim at providing the foundation for such a consensus. We derived the required functionality from multiple business scenarios set up in the Adaptive Services Grid (ASG) project.

With the expectable growth of the number of Web services available on the WWW and service repositories, the need for mechanisms that enable the automatic organization and discovery of services becomes increasingly important. Service classification using standard or proprietary taxonomies is a common and simple facility in this context, complementarily to more sophisticated service management retrieval techniques. In this paper we propose a heuristic approach for the semi-automatic classification of Web services, based on a three-level matching procedure between services and classification categories, assuming a corpus of previously classified services is available. An experimental test of the proposed techniques is reported, showing positive results.

A framework for modeling Semantic Web Service is proposed. It is based on Description Logic (DL), hence it is endowed with a formal semantics and, in addition, it allows for expressing constraints in service descriptions of different strengths, i.e. and . can be performed by matching DL descriptions, expressing both Hard and Soft constraints, and exploiting DL inferences. Additionally, a method for solving the problem of services is proposed which is based on the use of a semantic similarity measure for DL. This method can rank (matched) service descriptions on the grounds of their semantic similarity w.r.t. the service request, by preferring those that are able to better satisfy both Hard and Soft Constraints.

In the last few years there has been an increasing interest in studying ontology evolution and versioning for the World Wide Web, in particular, applied to OWL. However, little attention has been given to the problem of Web services evolution, with a focus on OWL-S, an ontology of services recently proposed. In this paper, we show that recent work on Temporal RDF can be extended to support versioning of an ontology of services. We introduce a formal model and a query language that allow accessing different versions of an OWL-S specification. We present the language semantics and discuss complexity issues. We show how our proposal can be implemented within the OWL-S framework.

is the most popular language for describing business process and business interaction based on Web services for inter-organizational cooperation. Nevertheless, requires a static binding of services to the flows. We propose in this paper a new approach enabling dynamic binding. This approach consists of, first, providing a high-level description of process, second, abstracting the process behavior using symbolic observation graphs and third providing an efficient algorithm for symbolic observation graphs matching which is used for binding dynamically business processes.