A Formal Methodology to Specify Hierarchical Agent-Based Systems

In this paper we introduce a formal framework to specifyagent-based systems where each agent is specialized ina single task that will be fulfilled by making calls to other simpler agents. In other words, we are interested in systems that can perform a task by subdividing it in easier tasks and by using the knowledge about each agent already introduced in the system. The idea is to prefabricate a basic structure that can be reused by either changing the main goal or by adding several different specialized agents. The main characteristic of our methodology is that each complex agent contains a schematic definition of other agents. Each agent is thus able to retain and produce certain information, such as the time needed to accomplish a certain task, taking into account a given set of agents and resources. This allows to quickly produce information regarding the necessities in resources and derive the demands to other subsystems.In order to increase the applicability of our approach, we have fully implemented a tool that allows us to graphically specify complex systems. In addition, the tool allows us to simulate the behavior of the specified systems so that some interesting properties, such as starvation and maximal progress, can be studied.