Optimum gauges of components in a vehicle side structure that meet minimum roof crush test requirement and side impact crashworthiness analysis (SICE) requirements with minimal mass are identified using a global optimization algorithm. A grouping of iterations, wherein each iteration contains input components of varying thicknesses, is simulated using the roof crush and SICE models. A self adaptive evolution optimization algorithm is used to generate additional groupings of iterations based on intermediate optimum results of a previous grouping. The additional groupings are simulated one or more times to identify a global optimum thickness of components in a vehicle side structure.