Analysing and designing whole-farm systems can greatly be enhanced by using simulation platforms that support representation of management decision-making processes. As manager of a purposive system, a farmer reasons his actions on the basis of a deliberated context-dependent course of actions setup to integrate biological, managerial and technical constraints specific to the farm and its environment. This paper presents a system-based model of such deliberative decision-making behavior based on the DEVS (Discrete Event System Specification) formalism. The modeling of farmer’s decision-making is addressed using the Belief-Desire-Intention (BDI) agent paradigm that provides a theoretical framework to articulate respectively the informational, motivational and intentional drivers underlying decisionmaking in an open (dynamic) environment. The functioning of such a management process is illustrated through the example of scheduling and coordinating the technical activities involved in a corn production system.