Emerging trends in applications with the requirement of considerable computational performance and decreasing time-to-market have urged the need of multiprocessor systems. With the increase in number of processor there is an increased demand to efficiently control the energy and power budget of such embedded systems as well. Dynamic voltage frequency scaling (DVFS) strategies permits to control this budget by actively changing the power consumption profile of the system. These techniques exploit the execution times variation of Real-time applications for dynamically adjusting the voltage and frequency of processors in order to reduce power and energy consumption. This paper presents one DVFS strategy called Dynamic slack reclamation (DSR) for real time applications. It is based on detecting early completion of tasks. DSR determines the amount of dynamic slack (if any) by comparing the worst-case execution requirement of a tasks job with its actual execution requirements. Experimental results will be extracted from the simulation of MPSoC architectures using the SoCLib platform; they show that DSR approach gives better power consumption performance.