James Truskin of Fiat Chrysler Automobiles presents Altair's C123 process to create Simplified Loadpath Models (SLMs) for advanced body in white (BIW) design. These concepts provide a highly flexible and rapid platform to explore body structure loadpath alternatives and performance: weight optimization. The C2/SLM modeling process combines higher order Beam and Bush finite elements with coarsened Shell-meshed panels to represent the body structure. FCA US LLC has understood and validated the C2 process for a BIW, and correlated key structural performance metrics to higher order, detailed Finite Element (FE) models. While the benefits of loadpath optimization through Beam element parameter variation is well-documented, and applied extensively for these types of models, this presentation provides a better understanding of the sensitivities and influence of joint stiffnesses on key body structure attributes to promote more intelligent and efficient body structure joint designs.