Giacomo Piccinelli

Dynamic service aggregation in electronic marketplaces

Abstract Electronic marketplaces represent a significant example for the evolution of the Internet from technical infrastructure to business enabler. Built on top of open standards like XML and value-added services like catalogue, negotiation, and transaction management, electronic marketplaces are the new hubs for business interaction. In first-generation electronic marketplaces service providers post information about their products, and service consumers post information about their needs. The matching is based on a market-dependent ontology, and standardised negotiation processes are supported by market mechanisms like auctions and exchanges. The final result is a one-to-one business relationship managed directly by the parties, outside the boundaries of the electronic marketplace. For second-generation electronic marketplaces the focus shifts to complete solutions. The capability to aggregate multiple services in order to match a specific service request should be provided as an internal service from electronic marketplaces. As an alternative, the electronic marketplaces should at least enable specific service providers to sustain effectively aggregation-oriented business models. After an overview of electronic marketplaces, we introduce the concept of e-services as electronic virtualisation of standard business services. We then present DySCo (Dynamic Service Composer), which includes a model and a reference infrastructure for e-service management and composition. Based on DySCo, a prototype has been developed for dynamic service aggregation through negotiation in multiple marketplaces. The prototype is presented, and the implications of the underlying business model are discussed.

Service provision and composition in virtual business communities

Service provisioning is at the base of the business economy and is a major driver for business-to-business interaction. The strong competition induced by market globalisation is forcing businesses to concentrate on their core competencies and to rely on specialised third parties for the provisioning of corollary service infrastructure. New expectations and opportunities are emerging for business uses of the Internet, and value chain optimisation is a priority. The role that the Internet is playing in the business service market at the moment revolves around a one-to-one model. Once two businesses have established a relationship, the Internet mainly acts as communication channel. Efficiency is an important benefit offered by the electronic transactions format, but very little value is added to the transaction itself. The decision about the best provider for a service and the trust in its capability to deliver the quality expected are instead high-value components for business transactions. The aim of our research is to explore electronic service provision in business-to-business scenarios, focusing on multi-party service composition. A composition-oriented service model has been designed, and it is presented in this paper, together with a prototype of its support infrastructure.

Dynamic e-service composition in DySCo

Until recently, the Internet was dominated by Web sites and store-fronts. We have now entered the next Internet evolution: e-services. E-services are modular, nimble electronic services that perform work, achieve tasks or complete transactions. The first step to turn an existing asset or service into an e-service revolves around accessibility. The virtualisation of the service provides communication channels that support automated conversational capabilities. The format of the service description allows automated discovery and enables automated negotiation on contractual terms and parameters. The second step towards the realisation of the full potential for the e-service vision focuses instead on composition and interaction orchestration. Beyond business conversations for point interactions, e-services can expose complete interaction processes. A service delivery is no longer a one-to-one (buyer-to-seller) relationship, but it now triggers the dynamic creation of business networks. In this paper, we first give a feeling about the e-service vision. We then propose a service model based on the ideas of functional incompleteness, multi-party orchestration and dynamic service composition. A prototype based on the proposed model, called DySCo (Dynamic Service Composition) is presented.

Web service interfaces for inter-organisational business processes an infrastructure for automated reconciliation

For the majority of front-end e-business systems, the assumption of a coherent and homogeneous set of interfaces is highly unrealistic. Problems start in the back-end, with systems characterised by a heterogeneous mix of applications and business processes. Integration can be complex and expensive, as systems evolve more in accordance with business needs than with technical architectures. E-business systems are faced with the challenge to give a coherent image of a diversified reality. Web services make business interfaces more efficient, but effectiveness is a business requirement of at least comparable importance. We propose a technique for automatic reconciliation of the Web service interfaces involved in inter-organisational business processes. The working assumption is that the Web service front-end of each company is represented by a set of WSDL and WSCL interfaces. The result of our reconciliation method is a common interface that all the parties can effectively enforce. Indications are also given on ways to adapt individual interfaces to the common one. The technique was embodied in a prototype that we also present.

e-service composition: supporting dynamic definition of process-oriented negotiation parameters

In the rapidly changing world of business-to-business (B2B) interaction, the e-service model triggers a new way to design and implement business services. While the capabilities required to implement a service stay constant, the set of companies providing these capabilities can change dynamically. Even when the companies stay the same, they may want to cover different roles at different times. Automating the negotiation processes between companies become crucial. We present a distributed negotiation system, which allows a service provider to dynamically subcontract aspects of its service to other providers and to determine the price to pay each. The system takes the description of the service in the form of a complete business workflow, together with a set of roles that participate in this workflow. Firstly, it decomposes the workflow into a set of process descriptions (projections) specialised for each possible subset of the roles involved in the original workflow. Each projection represents the view a potential subcontractor has over the workflow. The system then conducts a reverse combinatorial auction to allow subcontractors to offer to play a given set of roles, and fulfil the process associated with it in return for a payment.

Workflow: a language for composing web services

The introduction of Web Services has a profound impact on component models. The interaction processes behind a service become integral part of the component type, and as such formally described and automatically manageable. Workflow emerges as the reference model for the description of interaction processes associated to individual web services. In the DySCo (Dynamic Service Composition) project, we investigate the use of workflow for both the modelling and implementation of composite solutions based on web services. Key aspect of DySCo is the separation between composition and coordination logic. In this paper, we discuss the composition model defined in DySCo, and a technology framework to enforce it.

The FRESCO framework: an overview

The dynamic composition of existing services into new services is at the core of service-oriented computing. The objective of FRESCO (Foundational Research on Service Composition) is to develop a framework that service providers can use in order to model, develop, and execute composite services. The FRESCO framework will include conceptual tools, such as models for service composition and aggregation. The framework will also include technology elements, such as an integrated development environment and specific components of the infrastructure for service execution. A methodology will be given for the use of the FRESCO framework in the development of composite service solutions. We describe the main aspects of the approach to service composition adopted in FRESCO.

Managing interaction concerns in Web-service systems

Web services dramatically increase the reach of E-business. A homogeneous model that spans internal as well as external resources enables uniform solutions to complex business problems. Yet, the complexity of Web-service-based systems increases exponentially with their scope. Separation of crosscutting concerns and active management of aspects are fundamental in Web-service-based solutions. In this paper, we first introduce Web services and the concept of business interaction concerns. We then propose a process-oriented approach to the modelling of aspects deriving from crosscutting business concerns. We focus on the dynamic nature of Web-service-based solutions, and the need for adaptive management of aspects. In particular, we propose a technique for the dynamic distribution of aspects across multiple Web-service components. The technique is based on explicit definition of process roles. The proposed approach has been used to build experimental solutions involving dynamic reconfiguration of a Web-service system. We present an application example in the context of supply-chain integration that was prototyped using the DySCo platform (Dynamic e-Service Composer).

A Model-Driven Architecture for Electronic Service Management Systems

Mainly on the wake of the Web Service initiative, electronic services are emerging as a reference model for business information technology systems. Individual applications retain core functions and technology base, but integration becomes crucial. A business service derives from the coordination of different business capabilities. The related electronic service derives from the integration of the different applications sustaining such capabilities. The effective realisation of an electronic service requires explicit modelling and active management of the relations between business capabilities and technical infrastructure. In this paper, we propose the notion of Electronic Service Management System (ESMS) as a framework for modelling and implementing electronic services. The notion of ESMS is substantiated by a workflow-oriented architecture, which we mainly derive from the experience of HP Service Composer and the DySCo (Dynamic Service Composer) research prototype. The architecture is defined in accordance with the OMG’s Model-driven Architecture (MDA) principles.

Service-oriented modelling for e-business applications components

The emerging trends for e-business engineering revolve around specialisation and cooperation. Successful companies focus on their core competences, and rely on a network of business partners for the support services required to compose a comprehensive offer for their customers. Modularity is crucial for a flexible e-business infrastructure, but related requirements seldom reflect on the design and operational models of business information systems. Software components are widely used for the implementation of e-business applications, with proved benefits in terns of system development and maintenance. We propose a service-oriented componentisation of e-business systems as a way to close the gap with the business models they support. Blurring the distinction between external services and internal capabilities, we propose a homogeneous model for the definition of e-business applications components. After a brief discussion on the foundational aspects of the approach, we present the process-based technique we adopted for component modelling. We then present an infrastructure compliant with the model proposed that we built on top of an EJB (Enterprise Java Beans) platform.