We present a statistical life-time description for digital systems, which is characterized by short term functional simulation. Temperature and IR-drops for each hardware task of the system are regarded based on a coarse RT-floor plan and a component wise prediction of the dynamic and leakage power. By iteratively updating threshold voltage and supply resistances, then dynamic and leakage power, then temperature and IR-drop distribution, electro-thermal coupling as well as long term degradation effects can be described.