David Kinny

The Gaia Methodology for Agent-Oriented Analysis and Design

This article presents Gaia: a methodology for agent-oriented analysis and design. The Gaia methodology is both general, in that it is applicable to a wide range of multi-agent systems, and comprehensive, in that it deals with both the macro-level (societal) and the micro-level (agent) aspects of systems. Gaia is founded on the view of a multi-agent system as a computational organisation consisting of various interacting roles. We illustrate Gaia through a case study (an agent-based business process management system).

A methodology for agent-oriented analysis and design

This paper presents a methodology for agent-oriented analysis and design. The methodology is general, in that it is applicable to a wide range of multi-agent systems, and comprehensive, in that it deals with both the macro-level (societal) and the micro-level (agent) aspects of systems. The methodology is founded on the view of a system as a computational organisation consisting of various interacting roles. We illustrate the methodology through a case study (an agent-based business process management system).

A Formal Specification of dMARS

The Procedural Reasoning System (PRS) is the best established agent architecture currently available. It has been deployed in many major industrial applications, ranging from fault diagnosis on the space shuttle to air traffic management and business process control. The theory of PRS-like systems has also been widely studied: within the intelligent agents research community, the belief-desire-intention (BDI) model of practical reasoning that underpins PRS is arguably the dominant force in the theoretical foundations of rational agency. Despite the interest in PRS and BDI agents, no complete attempt has yet been made to precisely specify the behaviour of real PRS systems. This has led to the development of a range of systems that claim to conform to the PRS model, but which differ from it in many important respects. Our aim in this paper is to rectify this omission. We provide an abstract formal model of an idealised dMARS system (the most recent implementation of the PRS architecture), which precisely defines the key data structures present within the architecture and the operations that manipulate these structures. We focus in particular on dMARS plans, since these are the key tool for programming dMARS agents. The specification we present will enable other implementations of PRS to be easily developed, and will serve as a benchmark against which future architectural enhancements can be evaluated.

A methodology and modelling technique for systems of BDI agents

The construction of large-scale embedded software systems demands the use of design methodologies and modelling techniques that support abstraction, inheritance, modularity, and other mechanisms for reducing complexity and preventing error. If multi-agent systems are to become widely accepted as a basis for large-scale applications, adequate agent-oriented methodologies and modelling techniques will be essential. This is not just to ensure that systems are reliable, maintainable, and conformant, but to allow their design, implementation, and maintenance to be carried out by software analysts and engineers rather than researchers. In this paper we describe an agent-oriented methodology and modelling technique for systems of agents based upon the Belief-Desire-Intention (BDI) paradigm. Our models extend existing Object-Oriented (OO) models. By building upon and adapting existing, well-understood techniques, we take advantage of their maturity to produce an approach that can be easily learnt and understood by those familiar with the OO paradigm.

Planned Team Activity

Agents situated in dynamic environments can be supplied in advance with a repertoire of plans that permit them to rapidly generate appropriate sequences of actions in response to important events. When agents can form teams, new problems emerge regarding the representation and execution of joint actions. In this paper we introduce a language for representing joint plans for teams of agents, we describe how agents can organize the formation of a suitably skilled team to achieve a joint goal, and we explain how such a team can execute these plans to generate complex, synchronized team activity. The formalism provides a framework for representing and reasoning about joint actions in which various approaches to co-ordination and commitment can be explored.

Modelling and Design of Multi-Agent Systems

Agent technologies are now being applied to the development of large-scale commercial and industrial software systems. Such systems are complex, involving hundreds, perhaps thousands of agents, and there is a pressing need for system modelling techniques that permit their complexity to be effectively managed, and principled methodologies to guide the process of system design. Without adequate techniques to support the design process, such systems will not be sufficiently reliable, maintainable or extensible, will be difficult to comprehend, and their elements will not be re-usable.

The dMARS Architecture: A Specification of the Distributed Multi-Agent Reasoning System

The Procedural Reasoning System (PRS) is the best established agent architecture currently available. It has been deployed in many major industrial applications, ranging from fault diagnosis on the space shuttle to air traffic management and business process control. The theory of PRS-like systems has also been widely studied: within the intelligent agents research community, the belief-desire-intention (BDI) model of practical reasoning that underpins PRS is arguably the dominant force in the theoretical foundations of rational agency. Despite the interest in PRS and BDI agents, no complete attempt has yet been made to precisely specify the behaviour of real PRS systems. This has led to the development of a range of systems that claim to conform to the PRS model, but which differ from it in many important respects. Our aim in this paper is to rectify this omission. We provide an abstract formal model of an idealised dMARS system (the most recent implementation of the PRS architecture), which precisely defines the key data structures present within the architecture and the operations that manipulate these structures. We focus in particular on dMARS plans, since these are the key tool for programming dMARS agents. The specification we present will enable other implementations of PRS to be easily developed, and will serve as a benchmark against which future architectural enhancements can be evaluated.

Active Databases and Agent Systems - A Comparison

This paper examines Active Databases and Agent Systems, comparing their purpose, structure, functionality, and implementation. Our presentation is aimed primarily at an audience familiar with active database technology. We show that they draw upon very similar paradigms in their quest to supply reactivity. This presents opportunities for migration of techniques and formalisms between the two fields.

Motivational Attitudes of Agents: On Desires, Obligations, and Norms

Many papers about agents mention BDI as a reference logical model for agents, but this model does not offer a thorough formal account of the connections between the different modalities of Beliefs, Desires and Intentions. Of course, work such as that of Rao and Georgeff [14] and of Cohen and Levesque [5] has pointed to some specific constraints, but does not offer a complete logical theory that explains all possible connections between, e.g., goals and intentions. Another point of concern often voiced is the long-standing gap between the BDI logical model and practical agent implementations. Judged by its applicability, it might seem that the BDI model is becoming less important, due to the looseness of its connection to practical systems, and because of its failure to guide research into implementation directions in any obviously useful way.

The Psi Calculus: An Algebraic Agent Language

? is a novel algebraic language for the specification of agents, such as BDI agents, which employ a sense-compute-act computation cycle and stored plan execution as the basis of agent behaviour. It generalizes and extends agent architectures such as PRS and dMARS in several ways, and possesses a complete operational semantics covering all aspects of agent computation from intention step execution to the top-level control cycle. This is specified uniformly in process algebraic style by rewrite rules, and has certain safety, guarantee and compositionality properties which facilitate reasoning about agent program behaviour.