1. A computer-implemented method for analyzing design data representing optimization of real-world design for physical entities according to at least one criterion, the method comprising: at a computing device, receiving a first design variation and a second design variation; at the computing device, representing the design data of the first design variation and the second design variation by unstructured triangular surface meshes, wherein an unstructured triangular surface mesh is defined as a discrete representation of a boundary of a three dimensional design; at the computing device, calculating a displacement measure between corresponding vertices of the first design variation and the second design variation representing local differences between the first and second design variations, wherein the displacement measure is defined as a projection of a difference vector between the corresponding vertices onto a surface unit normal vector at a location of a corresponding vertex of the first design variation, wherein vertices define the location of corresponding surface points of the first design variation and the second design variation in three dimensional Euclidean space; at the computing device, calculating a performance difference between the first and second design variations, the performance difference represented by at least one criterion; at the computing device, quantifying correlation between the displacement measure and the performance difference; and at the computing device, outputting sensitivity information representing the correlation between the displacement measure and the performance difference, wherein the sensitivity information indicates which vertices of the design influence the performance of the design.