Yigal Hoffner

A Web Services Matchmaking Engine for Web Services

This paper concentrates on the issue of matchmaking in the context of web services. It provides a brief review of the difference between directory services and matchmaking facilities and explains why directories such as UDDI are important but insufficient for web services and need to be complemented with advanced matchmaking facilities. It discusses the requirements that web services place on matchmaking, namely symmetry of information exchange, the ability of each party to specify requirements of the other party, rich languages to describe services and their consumers as well as their demands, and the ability to dynamically update and configure what is being offered. These requirements are addressed by the Web Services Matchmaking Engine (WSME) – a powerful matchmaking engine capable of matching complex entities, and a Data Dictionary Tool for defining the language of the corresponding matchmaking process. The WSME matchmaking process and property and rules languages are described. An example of how a dynamic market for selling and buying Capacitors can be created with WSME is given. Finally, conclusions and possible future avenues of work are presented.

CrossFlow-cross-organizational workflow support for virtual organizations

CrossFlow is a European research project of the 4th ESPRTT Framework, aiming at cross-organizational workflow support for virtual enterprises. Virtual enterprises in the CrossFlow context are based on a service provider-consumer paradigm in which organizations (service consumers) can delegate tasks in their workflows to other organizations (service providers). The prime contractor in CrossFlow is IBM. Technology providers in the consortium are GMD-IPSI in Darmstadt, Germany, and the University of Twente in the Netherlands, who contribute their experience in groupware and workflow management. User partners are KPN Research in Groningen, the Netherlands, and AGFIL in Dublin, Ireland. Sema Group in Madrid, Spain, acts as industrial observer in the consortium. The CrossFlow project started in September 1998 and is planned to run for two years. The project covers the complete spectrum from requirements analysis to prototype assessment. In this paper, we briefly outline the goals of the project.

Web services and matchmaking

This paper discusses the need for detailed and comprehensive information models for web services that go a long way beyond currently available models. In this context, the need for this information creates several requirements of the matchmaking facilities needed to find matching business partners. The paper discusses these requirements and provides an assessment of some existing directory and matchmaking facilities. Finally, a working system that addresses these needs is presented.

CrossFlow: integrating workflow management and electronic commerce

The CrossFlow architecture provides support for cross-organisational workflow management in dynamically established virtual enterprises. The creation of a business relationship between a service provider organisation performing a service on behalf of a consumer organisation can be made dynamic when augmented by virtual market technology, the dynamic configuration of the contract enactment infrastructures, and the provision of fine-grained service monitoring and control.Standard ways of describing services and contracts can be combined with matchmaking technology to create a virtual market for such service provision and consumption. A provider can then advertise its services in the market and consumers can search for a compatible business partner. This provides choice in selecting a partner and allows the deferment of the decision to a point in time where it can be made on the most up-to-date requirements of the consumer and service offers in the market. The penalty for deferred decision making is the time to set up the infrastructure in each organisation for the dynamically established contract. Thus, a further aspect of CrossFlow was to exploit the contract in the dynamic and automatic configuration of the contract enactment and supervision infrastructures of the respective organisations and in linking them in a dynamic fashion. The electronic contract, which results from the agreement between the newly established business partners, completely specifies the intended collaboration between them. This includes fine-grained monitoring and control to allow tight co-operation between the organisations.

Supporting contract match-making

This paper describes a preliminary investigation of contracts with a view towards automating the process of contract match-making. A novel approach based on exploiting standard form contracts is described. The approach is shown to be implementable with current technology and a discussion of the CORBA/ODP trading service extensions necessary for implementing the proposed contract match-making is provided. A second approach based on standard contract clauses which overcomes some of the limitations of standard form contracts, is briefly outlined. The flexibility offered by this approach however, is accompanied by a considerable increase in the complexity of contract match-making. Both standard form contracts and standard contract clauses based match-making point towards an exciting area of future research.

Co-operation, contracts, contractual match-making and binding

Deals with the automation of parts of the process of setting up inter-organisational co-operations by electronic means. The paper presents a high-level model of the life-cycle of a co-operation between autonomous organisations. Contracts and their possible computer representations are investigated with a view towards implementing the contractual match-making and contractual binding stages of the life-cycle in a dynamic and rapid fashion. The mechanisms and processes which are necessary if these stages are to be automated are then described. Extensions to the ODP/CORBA trading service are shown to be necessary if trading is to be used in automating contractual match-making and binding. These extensions are described and it is shown how they can be exploited together with interception techniques for setting up the link between the co-operating organisations. These techniques can also be used to provide a range of decision-making and resource-allocation options concerning the co-operation set-up.

The Role of Contract and Component Semantics in Dynamic E-Contract Enactment Configuration

Dynamic establishment of electronic service contracts necessitates the dynamic configuration of a contract enactment system to either perform or consume the service. The more complex a service is, the more likely it is to be enacted by several components (or subsystems). Flexible configuration of a contract enactment system from components requires a blueprint defining which component type plays which role in the service’s enactment and how components are parameterised with contract elements. For this specification we need to understand the semantics of the contract and of the available components as well as rules for a correct composition of components. We investigate how components can be configured and dynamically assembled and propose an extensible service enactment model that provides the basis for component assembly. On the basis of this model the Internal Enactment Specification language is introduced for describing component compositions and parameterisations that can be processed by an automatic configuration mechanism.

TRANSFORMING AGREEMENTS INTO CONTRACTS

During the life cycle of a service consumer-provider relationship, agreements are reached in a variety of areas covering technical, service, business and legal issues. Although some of these agreements may be viewed as legally binding, it is unlikely that any of them will constitute a legal contract in the full sense of the word. It is often expedient to gather these agreements and create a legal contract out of them. Automating this process of contract generation can speed up the process and reduce the cost of legal expenses. In fact, the process of automated contract generation can also be useful outside the realm of web services, when agreements are made directly among people. We propose a way of transforming such agreements into contracts in a dynamic, efficient and speedy manner, using advanced forms of matchmaking technology in a novel way. This complements the other directions in which the agreements are to be used, namely configuration, instantiation, enactment supervision and relationship termination and evaluation.

In Search of the Right Partner

Finding matching customers and providers is an essential part of any dynamic e-business or virtual enterprise solution, Existing standards such as the CORBA Trading Service or emerging standards such as UDDI fall short of what is needed if the promise of dynamic e-business is to be fulfilled. This paper explores what is needed, and presents an implementation that satisfies those requirements.

The Typed Domain - a Recipe for Creating Virtual Enterprises

This paper presents an approach for describing inter-organisational relationships, based on the concept of the typed domain, which helps establish and enact successful relationships between partner organisations in specific domains. The typed domain consists of the relationship life cycle, projections and their documents, and domain building blocks of different granularity from which the relationship can be described, established and built. The relationships among the projections and the mappings among their various documents and related agreements can be exploited to structure and simplify the negotiation between partners. Furthermore, the mappings can be used to translate an agreement reached in one projection to agreements in other projections. This can be achieved using the typed domain as the context for the transformations and where necessary, involving further negotiation cycles.