Long-fiber (lengths > 1 mm) thermoplastic composites (LFTs) possess significant advantages over short fiber (< 1 mm) composites in terms of their mechanical properties while retaining their ability to be injection molded. Mechanical properties of LFTs are highly dependent on the microstructural variables imparted by the injection molding process including fiber orientation and fiber length distribution. As the fiber length increases, the mechanical properties of the composites containing discontinuous fibers can approach those of continuous fiber materials. Long fibers have the ability to deform, bend and even break during any stage of the injection molding process. There is a lack of knowledge about the effects of fiber length and fiber length distribution (FLD) on fiber orientation kinetics. This lack of information provides an opportunity to understand the length effect inherent in long fiber systems. The Bead-Rod fiber orientation model takes into account the flexibility of semi-flexible fibers that show small bending angles. In this model, a flexibility parameter representing the resistive bending potential is fiber length dependent. This work focuses on studying the influence of the fiber length variation on the performance of the Bead-Rod model. The Phelps and Tucker breakage model enables us to update the flexibility parameter based on the FLD data at each time step. From this aspect, the fiber breakage model is coupled with the fiber orientation model. The parameters within the stress tensor and orientation model are obtained via basic rheological measurements using simple shear flow in a sliding plate device and planar extensional flow in lubricated squeezing flow. Numerical simulation results involving a basic injection molding geometry are compared with the experimentally obtained fiber orientation and fiber breakage data. The bead-rod model shows significant improvement over the rigid rod model.