MAKKSim: Dealing with Pedestrian Groups in MAS-based Crowd Simulation Lorenza Manenti 1,2 , Sara Manzoni 1,2 , Giuseppe Vizzari 1,2 1 Complex Systems and Artificial Intelligence Research Center Dipartimento di Informatica, Sistemistica e Comunicazione Universita’ di Milano–Bicocca viale Sarca 336/14, 20126 Milano 2 Centre of Research Excellence in Hajj and Omrah, Umm Al-Qura University Makkah, Saudi Arabia {manenti, manzoni, vizzari}@disco.unimib.it Abstract—The paper presents MAKKSim, an agent-based tool for pedestrian dynamics simulation. The software is a second generation tool in which the presence of pedestrian groups and some cultural elements are explicitly modelled and can be set by the end-user. In this work, an overview on the MAKKSim model and software architecture is presented, by means of the definition of agent behaviours and the analysis of UML diagrams and end- user interface. I. I NTRODUCTION The simulation of pedestrians and crowd dynamics is a consolidated field of application for agent-based models: suc- cessful case studies can be found in the literature and off- the-shelf simulators are commonly employed by end-users, decision makers and consultancy companies. However, these tools are the result of a first generation of research efforts considering individuals, their interactions with the environment and among themselves, but generally neglecting or treating in a simplistic way aspects like (i) the impact of cultural heterogeneity among individuals and (ii) the effects of the presence of groups and particular relationships among pedestrians. The last point is, in fact, an open topic in the context of pedestrian modelling and simulation approaches [1] [2]: the implications of particular relationships among pedestrians in a crowd (e.g. the presence of groups) are generally not considered by current approaches. In this work we present MAKKSim (MAKKa pedestrian and crowd Simulator), a second-generation platform for pedestrian dynamics simulation based on an agent-based model in which groups of pedestrians and cultural attitude are explicitly con- sidered. MAKKSim and its relative model are the results of CRYSTALS project, a multidisciplinary research between the Center of Research Excellence in Hajj and Omrah (Saudi Ara- bia) and Complex Systems & Artificial Intelligence Research Center (Italy): the main focus of this project is the adoption of an agent-based pedestrian and crowd modelling approach to investigate meaningful relationships between the contributions of anthropology, cultural characteristics and existing results on the research on crowd dynamics, and how the presence of heterogeneous groups influences emergent dynamics in the context of the Hajj (i.e. the Pilgrimage toward Makka). In the specific context of the Hajj, the yearly pilgrimage to Makka that involves over 2 millions of people coming from over 150 countries, the presence of groups and the cultural differences among pedestrians represent two fundamental features of the reference scenario. Modelling groups and cultural aspects were the main re- quirements for MAKKSim development: with MAKKSim, we try to consider and explicitly model the impact of cultural heterogeneity among individuals by means of the introduction of proxemic-driven behaviour based on the theories by E.T. Hall [3] and by E. Canetti [4]: moreover, groups can be directly managed by the user by means of the definition of parameters related to group cohesion. Beyond groups and cultural atti- tude, other requirements were the integration of existing data specifying the spatial structure of the environment in which simulations must take place (e.g. CAD files), the possibility to export data about the simulations for analyses carried out by means of external programs, the possibility to provide an effective 3D visualization of the dynamics generated by the simulator. In the following, an introduction to MAKKSim platform is proposed, with an explanation of the model of pedestrians by means of agent behaviours and the description and man- agement of the environment. Then, an analysis of software architecture and relatives modules is presented, in order to show relationships among different elements of the model which the platform is based on. II. MAKKSIM MAKKSim is a software simulation platform developed by Complex Systems and Artificial Intelligence Research Center (CSAI) that supports the development of what-if scenarios about pedestrian dynamics within structured environments.