Lifetime reliability is an emerging concern in multiprocessor systems as escalating power density and hence temperature variation continues to accelerate wear-out leading to a growing prominence of device defects. In this paper, we propose a system-level approach that involves performance-aware mapping of multimedia applications on a multiprocessor system to jointly minimize energy consumption and temperature related wear-out. Fundamental to this approach is a simplified temperature model that incorporates not only the transient and the steady-state behavior (temporal effect), but also the temperature dependency on the surrounding cores (spatial effect). This model is validated against the temperature obtained using theHotSpot tool with transient and steady-state simulations, and is shown to be accurate within 5.5°C, leading to an MTTF estimation accuracy of an average 21 percent with respect to the state-of-the-art approaches. The proposed temperature model is integrated in a gradient-based fast heuristic that controls the voltage and frequency of the cores to limit the average and peak temperature leading to a longer lifetime, simultaneously minimizing the energy consumption. Lifetime computation considers task remapping, which is a common feature available in modern multiprocessor systems. A linear programming approach is then proposed to distribute the cores of a multiprocessor system among concurrent applications to maximize the lifetime. Experiments conducted with a set of synthetic and real-life applications represented as synchronous data flow graphs demonstrate that the proposed approach minimizes energy consumption by an average 24 percent with 47 percent increase in lifetime. For concurrent applications, the proposed lifetime-aware core distribution results in an average 10 percent improvement in lifetime as compared to performance-based core distribution.