Steel Slit Panel Frames (SSPFs) are an innovative and resilient lateral force resisting system. Steel Slit Panels (SSPs) are bolted to the beams and act as replaceable seismic fuses, dissipating energy through flexural yielding in links between vertical rows of slits. SSPFs have shown promise as a lateral force resisting system with ductile behavior and good energy dissipation up to 5% to 7% lateral drifts. In addition, they offer architectural flexibility, ease of fabrication and erection, and have the potential to be used as seismic retrofit option. The present research has been focused on developing simplified models of this system in OpenSees and validating these models with available experimental results. The simplified models make use of the nonlinear displacement based elements modified at University of Sydney. These models can capture yielding in the elements, flexural buckling and lateral torsional buckling of the elements, lateral torsional buckling of the panels, fracture of the elements and corresponding strength and stiffness degradation. A guideline for the simplified modeling of this system is presented. A computational parametric study of a 3 story prototype building is conducted to establish the effects of beam-panel stiffness ratio, beam lateral bracing, and two types of beam-SSP connections, on the system performance. Such parameters are critical for the ductile design of other lateral force resisting systems and so are chosen to be explored for this system. Secondary parameters of plastic hinging in the beams, gravity loads, and additional stiffeners in the SSPs are also considered in this study. Outcomes of this research include understanding of significant parameters for ductile system behavior, requirements for acceptable performance of this system, and preliminary seismic design provisions for this system.