. The notion of society should play a central role in agent-oriented software engineering as a first-class abstraction around which complex systems can be designed and built as multi-agent systems. We argue that an effective agentoriented methodology should account for inter-agent aspects by providing engineers with specific abstractions and tools for the analysis and design of agent societies and agent environments. In this paper, we outline the SODA agent-oriented methodology for the analysis and design of Internet-based systems. Based on the core notion of task, SODA promotes the separation of individual and social issues, and focuses on the social aspects of agent-oriented software engineering. In particular, SODA allow the agent environment to be explicitly modelled and mapped onto suitably-defined agent infrastructures. 1

Despite all the research done in the last years on the development of methodologies for designing MAS, there is no methodology suitable for the specification and design of MAS in complex domains where both the agent view and the organizational view can be modelled. Current multi-agent approaches either take a centralist, static approach to organizational design or take an emergent view in which agent interactions are not pre determined, thus making it impossible to make any predictions on the behavior of the whole systems. Most of them also lack a model of the norms in the environment that should rule the (emergent) behavior of the agent society as a whole and/or the actions of individuals. In this paper, we propose a framework for modelling agent organizations, Omni , that allows the balance of global organizational requirements with the autonomy of individual agents. It specifies

Organisations can be defined as a set of entities regulated by mechanisms of social order and created by more or less autonomous actors to achieve common goals. Multi-agent systems are a natural choice to design organisational systems due to the proactive and autonomous behaviour of agents. However, in business environments it is necessary to consider the behaviour of the global system and the collective aspects of the domain. In this paper, we argue that multi-agent systems should be designed around organisational co-ordination frameworks that reflect the co-ordination structures of the particular organisation. As in human societies, we argue that norms and institutions are a way for agent societies to cope with the challenge of social order. Through institutions, conventions and interaction patterns for the co-ordination of agents can be specified, monitored and managed.

The Agent Society framework that we have developed distinguishes between the mechanisms though which the structure and global behavior of the model is described and coordinated, and the aims and behavior of the serviceproviders (agents) that populate the model. In this framework contracts are used to integrate the top-down specification of organizational structures with the autonomy of participating agents. In this paper we introduce LCR, a very expressive logic for describing interaction in multi-agent systems. We also show how LCR behaves in contrary-to-duty situations common to deontic logic frameworks. LCR makes it possible to check whether agents in an agent society follow some desired interaction patterns and whether desired social states are preserved by agent activity. LCR is used as a formal basis for the framework for agents societies that we are developing.

Agent orientation is currently pursued primarily as a software paradigm. Software with characteristics such as autonomy, sociality, reactivity and proactivity, and communicative and cooperative abilities are expected to offer greater functionality and higher quality, in comparison to earlier paradigms such as object orientation. Agent models and languages are thus intended as abstractions of computational behaviour, eventually to be realized in software programs. However, for the successful application of any software technology, the software system must be understood and analyzed in the context of its environment in the world. This paper argues for a notion of agent suitable for modelling the strategic relationships among agents in the world, so that users and stakeholders can reason about the implications of alternate technology solutions and social structures, thus to better decide on solutions that address their strategic interests and needs. The discussion draws on recent work in requirements engineering and agent-oriented methodologies. A small example from telemedicine is used to illustrate.

In this paper, we propose a framework for modelling agent organizations, Omni, that allows the balance of global organizational requirements with the autonomy of individual agents. It specifies global goals of the system independently from those of the specific agents that populate the system. Both the norms that regulate interaction between agents, as well as the contextual meaning of those interactions are important aspects when specifying the organizational structure. Omni integrates all this aspects in one framework. In order to make design of the multi-agent system manageable, we distinguish three levels of abstraction with increasing implementation detail. All dimensions of Omni have a formal logical semantics, which ensures consistency and possibility of verification of the different aspects of the system. Omni is therefore utmost suitable for the modelling of all types of MASfromopentoclosedenvironments. 1.

Organizations are changing at an ever-faster pace, as they try to keep up with globalization and the information revolution. Unfortunately, information systems technologies do not support system evolution well, making information systems a roadblock to organizational change. We propose to view information systems as social structures and define methodologies which develop and evolve seamlessly an information system within its operational environment. To this end, this paper proposes an ontology for information systems that is inspired by social and organizational structures. The ontology adopts components of the i* organizational modeling framework, which is founded on the notions of actor, goal and social dependency. Social patterns, drawn from research on cooperative and distributed architectures, offer a more macroscopic level of social structure description. Finally, the proposed ontology includes organizational styles inspired from organization theory. These are used not only to model the overall organizational context of an information system, but also its architecture. Social patterns and organizational styles are defined in terms of configurations of i* concepts. The research has been conducted in the context of the Tropos project.

We investigate the concept of artificial societies and identify a number of separate classes of such societies. These are compared in terms of openness, flexibility, stability, and trustfulness. The two most obvious types of artificial societies are the open societies, where there are no restrictions for joining the society, and the closed societies, where it is impossible for an "external agent" to join the society. We argue that whereas open societies supports openness and flexibility, closed societies support stability and trustfulness.

Abstract. Agent architectures have to cope with a number of internal properties (concerns), such as autonomy, learning, and mobility. As the agent complexity increases, these agent properties crosscut each other and the agent’s basic functionality. In addition, multi-agent systems encompass multiple agent types with heterogeneous architectures. Each of these agent types has different properties, which need to be composed in different ways. In this context, the separation and the flexible composition of agent concerns are crucial for the construction of heterogeneous agent architectures. Moreover the separation of agent concerns needs to be guaranteed throughout the different development phases, especially from the architectural to the implementation phase. Existing approaches do not provide appropriate support for the modularization of agent properties at the architectural stage, and do not promote a smooth transition to the system implementation. This paper presents an aspect-oriented method that allows for a better separation of concerns, supporting the systematic aspectization of agent properties through the architectural definition, detailed design and implementation. A multi-agent system for paper reviewing management is assumed as a case study through this paper to show the applicability of our proposal. 1

Electronic markets, dispute resolution and negotiation protocols are three types of application domains that can be viewed as open agent societies. Key characteristics of such societies are agent heterogeneity, conflicting individual goals and unpredictable behaviour. Members of such societies may fail to, or even choose not to, conform to the norms governing their interactions. It has been argued that systems of this type should have a formal, declarative, verifiable, and meaningful semantics. We present a theoretical and computational framework being developed for the executable specification of open agent societies. We adopt an external perspective and view societies as instances of normative systems. In this paper we demonstrate how the framework can be applied to specifying and executing a contract-net protocol. The specification is formalised in two action languages, the C+ language and the Event Calculus, and executed using respective software implementations, the Causal Calculator and the Society Visualiser. We evaluate our executable specification in the light of the presented case study, discussing the strengths and weaknesses of the employed action languages for the specification of open agent societies.