Representing Conversations for Scalable Overhearing

Open distributed multi-agent systems are gaining interest in the academic community and in industry. In such open settings, agents are often coordinated using standardized agent conversation protocols. The representation of such protocols (for analysis, validation, monitoring, etc) is an important aspect of multi-agent applications. Recently, Petri nets have been shown to be an interesting approach to such representation, and radically different approaches using Petri nets have been proposed. However, their relative strengths and weaknesses have not been examined. Moreover, their scalability and suitability for different tasks have not been addressed. This paper addresses both these challenges. First, we analyze existing Petri net representations in terms of their scalability and appropriateness for overhearing, an important task in monitoring open multi-agent systems. Then, building on the insights gained, we introduce a novel representation using Colored Petri nets that explicitly represent legal joint conversation states and messages. This representation approach offers significant improvements in scalability and is particularly suitable for overhearing. Furthermore, we show that this new representation offers a comprehensive coverage of all conversation features of FIPA conversation standards. We also present a procedure for transforming AUML conversation protocol diagrams (a standard human-readable representation), to our Colored Petri net representation

Workshop on Modelling of Objects, Components, and Agents, Aarhus, Denmark, August 27-28, 2001

This booklet contains the proceedings of the workshop Modelling of Objects, Components, and Agents (MOCA'01), August 27-28, 2001. The workshop is organised by the CPN group at the Department of Computer Science, University of Aarhus, Denmark and the "Theoretical Foundations of Computer Science" Group at the University of Hamburg, Germany. The papers are also available in electronic form via the web pages: http://www.daimi.au.dk/CPnets/workshop01

Start Time and Duration Distribution Estimation in Semi-Structured Processes

Semi-structured processes are business workflows, where the execution of the workflow is not completely controlled by a workflow engine, i.e., an implementation of a formal workflow model. Examples are workflows where actors potentially have interaction with customers reporting the result of the interaction in a process aware information system. Building a performance model for resource management in these processes is difficult since the required information is only partially recorded. In this paper we propose a systematic approach for the creation of an event log that is suitable for available process mining tools. This event log is created by an incrementally cleansing of data. The proposed approach is evaluated in an experiment

Developing Agent Interaction Protocols with PRALU

The purpose of the paper is to explore the possibility of applying existing formal theories of description and design of distributed and concurrent systems to interaction protocols for real-time multi-agent systems. In particular it is shown how the language PRALU, proposed for description of parallel logical control algorithms and rooted in the Petri net formalism, can be used for the modeling of complex concurrent conversations between agents in a multi-agent system. It is demonstrated with a known example of English auction on how to specify an agent interaction protocol using considered means

A group learning management method for intelligent tutoring systems

In this paper we propose a group management specification and execution method that seeks a compromise between simple course design and complex adaptive group interaction. This is achieved through an authoring method that proposes predefined scenarios to the author. These scenarios already include complex learning interaction protocols in which student and group models use and update are automatically included. The method adopts ontologies to represent domain and student models, and object Petri nets to specify the group interaction protocols. During execution, the method is supported by a multi-agent architecture

Software Agent Architecture for Managing Inter-Organizational Collaborations

The growing importance of cooperation among organizations, as a result of globalization, current market opportunities and technological advances, encourages organizations to dynamically establish inter-organizational collaborations. These collaborations are carried out by executing collaborative business processes among the organizations. In this work we propose an agent-based software architecture for managing inter-organizational collaborations. Two types of agents are provided: the Collaboration Administrator Agent and the Process Administrator Agent. The former allows organizations setting up collaborations. The latter allows organizations executing collaborative business processes. A Colored Petri Net model specifying the role, which an organization fulfills in a collaborative process, is used to carry out the behavior of the Process Administrator Agent that represents the organization. Planning and execution of the actions of the Process Administrator Agents are driven by a Colored Petri Net machine embedded to them. Thus, Process Administrator Agents do not require to have defined at design-time the protocols they can support. In addition, we propose a model-driven development method for generating Colored Petri Net models from a collaborative process model defined as interaction protocol. Finally, an implementation of the agent-based software architecture and methods based on model-driven development are presented.La creciente importancia de la cooperación entre las organizaciones, como consecuencia de la globalización, las oportunidades actuales de mercado y los avances tecnológicos, alienta a las organizaciones a establecer en forma dinámica colaboraciones inter-organizacionales. Estas colaboraciones se llevan a cabo mediante la ejecución de procesos de negocio colaborativos entre las organizaciones. En este trabajo de investigación se propone una arquitectura basada en agentes de software para la gestión de colaboraciones inter-organizacionales. La arquitectura provee dos tipos de agentes: el Agente Administrador de Colaboraciones y el Agente Administrador de Proceso. El primer agente permite a las organizaciones a establecer colaboraciones. El segundo agente habilita a las organizaciones ejecutar procesos de negocio colaborativos. El rol que una organización desempeña en un proceso colaborativo es especificado mediante un modelo de redes de Petri coloreadas. Este modelo es usado para dirigir el comportamiento del Agente Administrador de Proceso, el cual representa a una organización. La ejecución de los planes y las acciones del Agente Administrador de Proceso son dirigidas mediante una máquina de redes de Petri coloreadas embebida en el agente. Entonces, los Agentes Administrador de Proceso no requieren tener definido en tiempo de diseño los protocolos que dan soporte a su comportamiento. Adicionalmente, se propone un método basado en el desarrollo dirigido por modelos para la generación en forma automática de modelos de redes de Petri coloreadas a partir de un modelo de procesos de negocio colaborativo definido como protocolo de interacción. Finalmente, la implementación de la arquitectura y los métodos basados en el desarrollo dirigido por modelos son presentados.Fil: Tello Leal, Edgar. Universidad Autónoma de Tamaulipas; MéxicoFil: Chiotti, Omar Juan Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Desarrollo y Diseño (i); ArgentinaFil: Villarreal, Pablo David. Universidad Tecnologica Nacional. Facultad Regional Santa Fe. Centro de Investigacion y Desarrollo de Ingenieria En Sistemas de Informacion; Argentin

Adding debugging support to the Prometheus methodology

This paper describes a debugger which uses the design artifacts of the Prometheus agent-oriented software engineering methodology to alert the developer testing the system, that a specification has been violated. Detailed information is provided regarding the error which can help the developer in locating its source. Interaction protocols specified during design, are converted to executable Petri net representations. The system can then be monitored at run time to identify situations which do not conform to specified protocols. A process for monitoring aspects of plan selection is also described. The paper then describes the Prometheus Design Tool, developed to support the Prometheus methodology, and presents a vision of an integrated development environment providing full life cycle support for the development of agent systems. The initial part of the paper provides a detailed summary of the Prometheus methodology and the artifacts on which the debugger is based