What is new with the activity world view in modeling and simulation? using activity as a unifying guide for modeling and simulation

Among the four well known conceptual frameworks for simulation, the activity scanning strategy is one possible world-view. Other usual strategies (process-based, event-based or three phase approach) can be used. Depending on the problem to be modeled, one view will be more adapted and ease the implementation. In a system specification, the integration of the usual world-views should be clear. The concept of activity is shared by all the known conceptual frameworks and is a key aspect of simulation. In this paper we emphasize on what is new with activity-based modeling and simulation, and provide new definitions. In addition, we propose a multi-level life cycle adapted to activity aware simulations.