Abstract—Agents are becoming one of the most important topics in distributed and autonomous decentralized systems, and there are increasing attempts to use agent technologies to develop large-scale commercial and industrial software systems. The complexity of such systems suggests a pressing need for system modeling techniques to support reliable, maintainable, and extensible design. G-nets are a type of Petri net defined to support system modeling in terms of a set of independent and loosely-coupled modules. In this paper, we customize the basic G-net model to define a so-called “agent-based G-net ” that can serve as a generic model for agent design. Then, to progress from an agent-based design model to an agent-oriented model, new mechanisms to support inheritance modeling are introduced. To illustrate our formal modeling technique for multiagent systems, an example of an agent family in electronic commerce is provided. Finally, we demonstrate how we can use model checking to verify some key behavioral properties of our agent model. This is facilitated by the use of an existing Petri net tool. Index Terms—Multiagent systems, Petri net, G-net, design model, electronic commerce, model checking. 1

Abstract. How to specify agent’s intelligent behaviour is a challenging open problem in the development of agent-based systems. This paper presents a case study of developing the formal specification of the evolutionary multi-agent ecosystem Amalthaea developed at MIT Media Lab. A diagrammatic notation is used for the development of agent models and to derive a formal specification of the system in SLABS, which is a formal specification language for agent-based systems. 1

Abstract. One of the most appealing features of multiagent technology is its natural way to modularise a complex system in terms of multiple, interacting and autonomous components. As a natural extension of classes, castes introduced in the formal specification language SLAB provide a language facility that provides modularity in the formal specification of multiagent systems. A caste represents a set of agents of common structural and behavioural characteristics. A caste description defines the tasks that the agents of the caste are capable of, the rules that govern their behaviour, and the environment that they live in. The inheritance relationship between castes defines the sub-group relationship between the agents so that special capabilities and behaviours can be introduced. The instance relationship between an agent and a caste declares that an agent is a member of a caste. This paper discuses how the caste facility can be employed to specify multiagent systems so that the notion of roles, organisational structures of agent societies, communication and, collaboration protocols etc. can be naturally represented. 1.

Summary. Agent technology is widely perceived to be a viable solution for largescale industrial and commercial applications in dynamic environments such as the Internet. However, the lack of rigour and language support in the analysis, specification, design and implementation of multi-agent systems has hampered the wide adoption of agent technology. This paper proposes a model-driven approach to the development of multi-agent systems. It combines graphic modelling with formal specification through automated tools. The paper reports an agent-oriented modelling language CAMLE and the automated tools in its modelling environment. Two aspects of particular importance in the model-driven development methodology are addressed in this paper. The first is the definition and implementation of consistency constraints on graphic models. The second is the automated transformation of graphic models into formal specifications. 1

Multi-Agent Systems (MAS) have become increasingly mature, but this maturity does not make the traditional Object Oriented (OO) approaches obsolete. On the contrary, building MAS in combination with OO constructs allows the reuse of existing components. Similarly, OO methodologies can benefit from extension towards an agent abstraction and so make use of the methods and tools for MAS. The Agent-Rule-Class (ARC) framework is proposed as an approach that builds agents upon traditional OO system components and makes use of business rules to dictate agent behaviours, aided by the OO components. By modelling agent knowledge in business rules, the proposed paradigm provides a straightforward means to develop agent-oriented systems based on the existing object-oriented systems and offers features that are otherwise difficult to achieve in OO systems. A Structural Model and a Behavioural Model are the central components in the ARC framework for agent-oriented system modelling. A supporting tool has been developed to ensure that agents implement up-to-date requirements from business people, reflecting desired current behaviours, without the need for frequent system rebuilds. The ARC framework provides a complete MAS development process supported by a new process model more suited to collaboration between OO developers, Agent Oriented (AO) developers and domain experts. The main outcome of using ARC is better adaptivity. The ARC framework is illustrated with a rail track example.

Abstract. Emergent behaviour (EB) is a common phenomenon in multi-agent systems (MAS) where autonomous agents perform certain actions with only limited access to local information and make decisions individually, while the whole system demonstrates properties and behaviours that have strong global features. Because of the huge gap between individual agents ’ properties and behaviours and those of the whole system, specifying and reasoning about EBs are difficult. In this paper, we propose a framework to the specification of and reasoning about EBs based on our previous work on the SLABS language for the formal specification of MAS. We investigate the uses of the scenario specification in SLABS for the definition of EBs of MAS and study the properties of scenario inclusion, scenario transition and scenario update. The uses of these properties in the proofs of MAS’ EBs are illustrated by an example. 1.

Abstract not found

Based on our previous work on the formal specification language SLABS as well as a methodology and modelling language for modelling and specifying multi-agent systems, we further investigate how diagrammatic models of multi-agent systems can be used to derive formal specifications in SLABS. The modelling language is further developed by introducing behaviour diagrams and scenario diagrams for modelling agents’ behaviour in various scenarios of their environment. It supports derivation of the specifications of agents’ behaviour through scenario analysis. The language and its usage are illustrated by an example of the evolutionary multi-agent ecosystem Amalthaea developed at MIT Media Lab. 1.

Abstract. TCOZ is a specification language that combines the strengths of Object-Z and Timed CSP with the goal of specifying distributed systems containing objects that act independently and concurrently. Such goals are similar to the goals of the autonomous agent paradigm, in which agents are entities in an environment that act independently of one another, concurrently, and work proactively to achieve certain goals. This paper discusses the suitability of several TCOZ constructs in specifying multi-agent systems, and presents a small, yet non-trivial case study of a multi-agent system specification using TCOZ. 1

Modularity and rigor are two key elements for multi-agent technology. Hong Zhu’s multi-agent system (MAS) development method provides proper language facilities supporting modularity. To enhance this method with rigor advocates a DL method to map the specification of MAS into a DL TBox. Thus, we can use the existing DL reasoners and systems to verify and validate some system’s properties. 1