It is uncommon to have openings near columns in flat slabs however the presence of openings exhibits excessive punching shear demand reducing the structural performance of flat slabs. This research work numerically investigates the use of various stud shear reinforcement orientation types and configurations to rehabilitate or restore lost flat slab structural performance due to the presence of opening cutouts. The experimental result reported in literature will be used for validation analysis using ANSYS nonlinear software program and further parametric study on stud variables such as a layer, orientation, and arrangement; and opening variables like a quantity, size, location, and patterns will be investigated to get insight into the performance of flat slab with and without an opening near columns. A total of thirty-one flat slab specimens with or without stud and openings were simulated. The accuracy of the finite element analysis method was verified by comparing the results in terms of failure load and crack pattern and showed good agreement with experimental test results. The FEA results indicated that due to stud shear reinforcement the restored punching shear carrying capacity of a reinforced concrete flat slab that was lost due to opening ranges from 16.53% to 26.7%, likewise the ductility of a reinforced concrete flat slab was enhanced by stud shear reinforcement. Additionally, the numerical values were compared with design code ES EN 2015. The results obtained by the ES EN 2015 standard were a tendency to underestimate the shear strength of the slabs, especially when there are openings. The FEA results showed that the equations’ punching shear resistance prediction for ES EN 2015 overestimated up to 157% in slabs. Numerical results confirmed the use of studs has strengthened the region near the openings and this is not always accounted for by the ES EN 2015 code.