Towards an Emergence-Driven Software Process for Agent-Based Simulation

‡ Partially supported by FCT/PRAXIS XXI, Portugal, grant number BD/21595/99. ¥ Partially supported by CNPq, Brazil, grant number 301041/95-4, and by project MAPPEL (PROTEM -CC, CNPq/NSF), grant number 680033/99-8. Abstract. In this paper we propose an emergence-driven software process for agent-based simulation that clarifies the traceability of micro and macro observations to micro and macro specifications in agent-based models. We use the concept of hyperstructures [1] to illustrate how micro and macro specifications interact in agent-based models, and we show that the reductionism/non-reductionism debate is important to understand the reliability of agent-based simulations. In particular, we show that the effort expended in the verification of agent-based simulations increases exponentially with the number of micro and macro specifications, and that the reliability assessment of non-anticipated results in simulation is in practice not possible. According to these results we claim to be impossible in practice to verify that an agent-based conceptual model has been implemented properly as a computational model, since one does not usually know what is the desired output a priori. We thus advocate that the classic process of verification, validation and exploration of non-anticipated results is not reliable in an agent-based simulation, and call into question the applicability of traditional software engineering methods to agentbased simulation.