THOMAS: A Service-Oriented Framework For Virtual Organizations E. del Val, N. Criado, C. Carrascosa, V. Julián, M. Rebollo, E. Argente, V. Botti ABSTRACT This paper describes the THOMAS framework, a useful frame- work for the development of virtual organizations, on the basis of a service-based approach. Categories and Subject Descriptors I.2.11 [Distributed Artificial Intelligence]: Multi-agent Systems Keywords Service-Oriented Architecture, Open Multi-Agent Systems, Virtual Organizations 1. SERVICE ORIENTED VIRTUAL ORGA- NIZATIONS Virtual Organizations (VOs) are a set of individuals and institutions that need to coordinate resources and services across institutional boundaries [1]. Thus, they are open sys- tems formed by the grouping and collaboration of heteroge- neous entities and there is a separation between form and function that requires defining how a behaviour will take place. As a consequence of the heterogeneity feature, orga- nizational concepts are needed for achieving the coordina- tion. In addition, system functionalities should be modelled as services in order to allow heterogeneous agents or other entities to interact in a standardized way. The integration of MAS and Service Technologies has been proposed as the basis for these new and complex systems [3]. The present demo represents a step forward on this direc- tion, providing a service-oriented framework specifically de- signed for the execution of VOs and based on the THOMAS architecture [2]. 2. THOMAS FRAMEWORK The THOMAS framework allows any agent to create a VO with the structure and norms needed, along with the demanding and offering services required. Its purpose is to obtain a product wholly independent of any internal agent platform, thus fully addressed for open systems. The frame- work is in charge of the management of the organization Cite as: THOMAS: A Service-Oriented Framework For Virtual Orga- nizations, E. del Val, N. Criado, C. Carrascosa, V. Julián, M. Rebollo, E. Argente and V. Botti, Proc. of 9th Int. Conf. on Autonomous Agents and Multiagent Systems (AAMAS 2010), van der Hoek, Kaminka, Luck and Sen (eds.), May, 10–14, 2010, Toronto, Canada, pp.  Copyright c  2010, International Foundation for Autonomous Agents and Multiagent Systems (www.ifaamas.org). All rights reserved. structure, norms and life cycle, as well as controlling the visibility of the offered and demanded services and the ful- filment of the conditions to use them. All the functionalities of the framework are offered as semantic web services which are classified into two different entities: the Organization Management System (OMS) and the Service Facilitator SF. Next, a general description of how services have been im- plemented in the THOMAS framework is presented. The specific implementation of both OMS and SF services and how these OMS and SF entities are encapsulated into agents to be accessible by other agents are also described. THOMAS Services are implemented as semantic web ser- vices, using Apache Axis2/Java c  as core engine for web services. More over, the use of RT-Java for providing time- bounded web services has been tested [4]. Each service has a semantic description in OWL-S c  which details the properties and capabilities of a web service in unambiguous, computer-interpretable form. It facilitates the automation of web service tasks, including automated service discovery, execution, composition and interoperability. 3. AGENT IMPLEMENTATION Both the OMS and SF functionalities have been imple- mented as semantic services and can be accessed using web service standards. In addition, OMS and SF agents, which are mainly gateways to the OMS and SF services, have been implemented in order to allow JADE TM agents to access the framework’s services. The logic of these agents has been im- plemented using the OWL-S API c  provided by Mindswap. This OWL-S API employs a Java API for programming ac- cess to read, execute and write OWL-S service descriptions. When the SF agent (or the OMS agent) receives a FIPA request message from a client, it employs the OWL-S API to access the service description in OWL-S and execute the correspondent web service. SF Implementation. The SF has to be able to register and manage the services provided by external agents. In or- der to make these services machine-understandable, seman- tic information is added as OWL-S descriptions for services and ontology specification in OWL c  for agent beliefs inter- change and the specification of service parameters. Thus, tools to handle semantic information have been added to the SF. JENA c  and SPARQL c  have been employed to manage all these semantic data in OWL. JENA provides a program- matic environment for RDF, RDFS and OWL, as well as an implementation of the RDF model interface that stores the triples persistently in a database. SPARQL has been used as language that queries the information held in the models 1631 1631-1632