Laser directed energy deposition is a promising additive manufacturing technique that has a huge potential in remanufacturing and restoration of high-value aerospace components. For sustainable repair, it is necessary to control the output parameters, such as deposition geometry and integrity in terms of residual stresses, dilution, defects, and distortion. Consequently, this thesis aims at understanding and modeling various physical phenomena underlying the laser deposition process to determine the quality and integrity of the deposition. A novel comprehensive modeling approach for both single track and multi-track deposition has been developed that captures the process accurately.