Simone Grega

WSMoD: A Methodology for QoS-Based Web Services Design

Web services are increasingly used as an effective means to create and streamline processes and collaborations among governments, businesses, and citizens. As the number of available Web services is steadily increasing, there is a growing interest in providing methodologies that address the design of Web services according to specific qualities of service (QoS) rather than functional descriptions only. In this paper, we present WSMoD (Web Services MOdeling Design), a methodology that explicitly addresses this issue. Furthermore, we exploit general knowledge available on services, expressed by ontologies describing services, their qualities, and the context of use, to help the designer in expressing service requirements. Ontologies are used to acquire knowledge among the entities involved in service design and to check the consistency of the Web service. The discussion of a QoS-based Web service design within a real case study bears evidence of the potentials of WSMoD.

A service re-design methodology for multi-channel adaptation

Many available services have been designed for a single-channel world, Web and Internet typically. In a real world scenario, an ever-growing number of users take advantage of different kinds of communication channels and devices. In this paper, we propose a methodology to formalize the re-design process of these services to support multi-channel access in different contexts. The methodology considers the channel characteristics, the location of users and the context of use to characterize the new services. It has been tested in a case study: the Italian National Project of Identification and Registration of Bovine Animals.

Service portfolio management: A repository-based framework

The paper discusses a framework for managing and evaluating ICT-enabled service portfolios along the service design phase. The framework adopts a service reuse perspective and it is made up of i) a model for the representation of a repository of services, ii) a model for the definition of a service portfolio representing current production lines of a service provider organization, iii) a set of metrics for service portfolio evaluation, and iv) a tool supporting managers in decision making for the achievement of design objectives. The proposed metrics and the tool are supposed to allow decision makers to get an improved view of the service design process. Furthermore, the framework supports managers in decision making for the achievement of production objectives as well as operational strategies, resulting in potential reuse initiatives, likewise. To provide evidence of the impacts of the proposed framework, experimental activities are discussed focusing on a real life case study, referring to an Italian small size service provider.

A reusable 3D visualization component for the semantic web

Ontology visualization and exploration is not a trivial task as many issues can affect the effectiveness of interactions. As ontologies are, in the general case, quite connected graphs where concepts are the nodes and semantic relationships the edges, the problems include space allocation, edge superposition, scene over-crowding, etc. In this paper we propose a solution for the visualization and the exploration of ontologies using a 3-dimensional space, where information is represented on a 3D view-port enriched by visual cues. Our visualization tool aims at tackling representation issues of ontology models (as space allocation or the completeness and read-ability of displayed information) by adopting different views, at different granularities, in order to grant a constant navigability of the rendered model. Each provided view represents semantic information according to a different, task-based visualization paradigm, at a suitable level of detail. Besides being primarily implemented as a Protégé plug-in, the proposed solution (named OntoSphere3D) is designed to be a reusable visualization component within Semantic Web applications; in fact, every scene can be exploited as a standalone facility that provides access to ontological data through an intuitive and appealing 3D interface. A case-study, is presented, where re-usability is demonstrated by integrating the OntoSphere3D visualization inside an Eclipse-based tool for Web Service design (called Web Services Design Tool) developed by some of the authors in the context of another research project.

Optimal enterprise data architecture using publish and subscribe

In medium-big enterprise it is quite typical that the database architecture is defined through a sequence of projects and realizations that result a number of different and sometime overlapping data sources. This trend is worsened by merger and acquisition activities that add in existing data architecture new data sources from external organizations. Data fragmentation reduces significantly the possibility to exploit organizational information assets and it needs the building of a data integration architecture. This architecture allows the organization to access to data stored by heterogeneous data sources and to manage updates through a unified view of this data. In this paper we present an original framework able to support the evolution of data architecture by identifying the optimal solution that maximize the quality of the overall architecture within a given cost threshold. In particular, we focus on Publish and Subscribe as solution for data architecture.

Alignment of Service Science and Service Oriented Computing: a Unified Interpretative Approach to Service Design and Planning

At the state of art, service ecosystems are seldom considered under a holistic perspective, whereas silos oriented perspectives prevail (the organizational level, the ICT level, and so on). Due to this separation of concerns, it is difficult to provide comprehensive solutions to plan service oriented initiatives combining models and solution developed at different levels. A significant problem in this scenario comes from the multi-faceted relationship between real services, which impact on the information system as a whole, and Service Oriented Computing (SOC), which is a paradigm to support ICT-based service automation and management. In this paper, we discuss an interpretative approach aiming at bridging the gap between services and SOC. The approach is based on a conceptual model called eGora*. The discussion is supported by a real life scenario based on previous on the field experimentations.

Quality Composition in Web-Service Design

Modern software components are asked to deliver their services over different communication channels and devices to support mobile and ubiquitous applications. Therefore, development processes that traditionally address only functional requirements must be revised by considering new aspects: quality of service (QoS), user profiles and technical characteristics of channels. Moreover, services obtained by the composition of simple services offered by different providers are getting growing importance. In this paper, we propose a hybrid technique to deal with quality evaluation in composite Web Service design. This work extends and integrates the single-service design process presented in previous papers.