TCAD prediction of the stress field generated by dislocation is crucial for the optimization of stressors for next generation logic devices. In this paper, we present a new hybrid approach for dislocation stress field calculation and its application to strained Si devices. New methodology combines an analytic stress field model for dislocation cores and consecutive FEM stress solving to get mechanical equilibrium. It was applied to the design optimization of dislocation stress memorization technique (D-SMT), its local layout effect (LLE) modeling, and the relaxation of lattice mismatch strain at Si/SiGe interface which degrades eSiGe stress. All the simulation results were verified with experimental results.