Simulation modelling allows one to assess management scenarios of agricultural systems. Beyond representing biophysical processes (material flows stemming from crops, animals and the environment) it is also crucial in such models to account for the farming activities to which they are tightly coupled. With this aim, it will be presented the representational features enabling human action to be simulated according to its two dimensions: time (based on Systems Dynamics) and space (based on Multi-Agent Systems). Integrating both approaches in a coherent modelling framework will be outlined. (Texte intégral)