To antagonize the outcome of the demographic and the appending structural change also, a human centered assistance sys tem, that means an assistance system, which is completely user orientated, is introduced. The assistance system is realizing a predictive situation recognition with the aid of the evaluation of embedded, local actuators and sensor networks, to regulate and even if necessary to initiate preventive interventions in the user’s environment. The key part of the assistance system is a hierarchical arrangement of functional layers with different capabilities; a main role is taken by the pro babilistic modeling of system inherent activities through stochastic processes. This is demonstrated by a simplified exam ple of emergency case detection including a following diagnosis process, to clarify the excellence and the current weak ness of the assistance system.