The scheduling of daily activities requires decisions to be made on which activities to conduct, where, when, for how long, and the transport mode involved. In a common conceptualization of the decision process, a multitude of time frames is involved. Longer term decisions determine the allocation of time across main activity categories as well as the profiling of institutionalized activities such as work and some leisure activities. The authors introduce a conceptual framework for modeling the formation of activity agendas that represents the results of such longer term decisions. The framework identifies the elementary decisions and arranges these decisions in a hierarchy. In the proposed system, the decisions are handled by a set of relatively autonomous interacting agents.