Abstract. It is generally accepted that the environment is an essential compound of multiagent systems (MASs). Yet the environment is typically assigned limited responsibilities, or even neglected entirely, overlooking a rich potential for the paradigm of MASs. Opportunities that environments offer, have mostly been researched in the domain of situated MASs. However, the complex principles behind the concepts and responsibilities of the environment and the interplay between agents and environment are not yet fully clarified. In this paper, we first give an overview of the state-of-the-art on environments in MASs. The survey discusses relevant research tracks on environments that have been explored so far. Each track is illustrated with a number of representative contributions by the research community. Based on this study and the results of our own research, we identify a set of core concerns for environments that can be divided in two classes: concerns related to the structure of the environment, and concerns related to the activity in the environment. To conclude, we list a number of research challenges that, in our opinion, are important for further research on environments for MAS. 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

Numerous methodologies for developing agent-based systems have been proposed in the literature. However, their application is still limited due to their lack of maturity. Evaluating methodologies' strengths and weaknesses plays an important role in improving them and in developing the "next-generation" of methodologies. This paper presents a comparison of three prominent agent-oriented methodologies: MaSE, Prometheus and Tropos. It is performed based upon an attribute-based framework which addresses four major areas: concepts, modelling language, process and pragmatics. The objectivity of the comparison is increased by including inputs from the authors of the methodologies using a questionnaire and by conducting an experimental evaluation of the methodologies.

Security Requirements Engineering is emerging as a branch of Software Engineering, spurred by the realization that security must be dealt with early on during the requirements phase. Methodologies in this field are challenging, as they must take into account subtle notions such as trust (or lack thereof), delegation, and permission; they must also model entire organizations and not only systems-to-be. In our previous work we introduced Secure Tropos, a formal framework for modeling and analyzing security requirements. Secure Tropos is founded on three main notions: ownership, trust, and delegation. In this paper we refine Secure Tropos introducing the notions of at-least delegation and trust of execution; also, at-most delegation and trust of permission. We also propose monitoring as a security design pattern intended to overcome the problem of lack of trust between actors. The paper presents a semantics for these notions, and describes an implemented formal reasoning tool based on Datalog. 1

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.

The last years have seen a number of proposals to incorporate Security Engineering into mainstream Software Requirements Engineering.

In the paper we study the dynamics of roles played by agents in multiagent systems. We capture role dynamics in terms of four operation performed by agents: `enactment', `deactment', `activate', and `deactivate'. The use of these operations are motivated, in particular for open systems. A formal semantics for these operations are provided. This formalization is aimed at serving as a basis for implementation of role dynamics in an agent programming language such as 3APL.

Several surveys indicate that a significant percentage of data warehouses fail to meet business objectives or are outright failures. One of the reasons for this is that requirement analysis is typically overlooked in real projects. In this paper we propose a goal-oriented approach to requirement analysis for data warehouses, based on the Tropos methodology. Two different perspectives are integrated for requirement analysis: organizational modeling, centered on stakeholders, and decisional modeling, focused on decision makers. Our approach can be employed within both a demand-driven and a mixed supply/demand-driven design framework: in the second case, while the operational sources are still explored to shape hierarchies, user requirements play a fundamental role in restricting the area of interest for analysis and in choosing facts, dimensions, and measures. The methodology proposed, supported by a prototype, is described with reference to a real case study. 1

Abstract. Tropos is an agent-oriented software methodology proposed in [1, 2]. The methodology is founded on the notions of agent and goal, and goal analysis is used extensively to support software development during different phases. This paper adopts a formal goal model defined and analyzed in [9, 15] to make the goal analysis process concrete through the use of forward and backward reasoning for goal models. The formal goal analysis is illustrated through examples, using an implemented goal reasoning tool.

Integrating security concerns throughout the whole software development process is one of today's challenges in software and requirements engineering research. A challenge that so far has proved difficult to meet. The major difficulty