Modeling Role-based Interactions for Agents

Abstract Software agents, thanks to their autonomy in carrying out tasks, are fruitfully exploited in large-scale distributed environments, such as the Internet. In such a scenario, interactions among agents are an issue that must be faced in an appropriate way. This paper proposes an interaction model based on roles, being a role a set of capabilities and an expected behavior. Modeling interactions by roles can simplify the design of the agent-based applications. A notation based on XML is adopted to support the definition and the exploitation of roles at different phases of the application development. Finally, an application example shows the effectiveness of the approach. 1 Introduction As software agents are spreading over distributed environments, and in particular over the Internet, new methodologies and tools are needed to support the development of agent-based applications. Such applications are usually composed of a multiplicity of agents, each one in charge of a small task that is part of the global goal. In this scenario, an important issue to be faced is the interaction among agents. In fact, the agents belonging to the same application need to interact and coordinate to carry out the global goal. Moreover, in an open scenario, agents belonging to different applications may need to interact, for instance, to compete for a resource. So, interactions can occur between agents of the same application, or between agents belonging to different applications, and such interactions must be modeled and managed in an appropriate way. Traditional approaches to agent interactions usually derive from adaptations of older models related to distributed systems, so they do not fit all the characteristics of the new scenario. This paper proposes a model for engineering agent interactions based on the concept of