The flexural strength of reinforced concrete (RC) beams is required to be upgraded due to many situations where additional loading is induced and strengthening becomes a must. The nonlinear finite element modeling was used in this study to fulfill the objective of flexural strengthening using an innovative system. The new system is a hybrid technique where steel fibers are mixed with polyvinyl-alcohol fiber-reinforced engineered cementitious composite (SPF-ECC) with steel reinforcing rebars. The SPH-ECC layer was applied with 50 mm thickness on three sides of the conventional RC beams (U-shaped). The optimization of strengthening system was optimized using different values of sensitive parameters, including the effect of beam depth (200, 275, and 350) mm, the presence of the strengthening system (with and without), and the steel reinforcement within the SPH-ECC layer (without, 2∅16, and 4∅16). Results were presented in terms of strength, serviceability, and failure modes for all stages (cracking, yielding, and ultimate) with detailed results presentation. In conclusion, the performance of the RC beams could be significantly upgraded even in the presence of space limitations using a simple combination of material properties and geometrical dimensions.