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: receiving a first design modification and a second design modification; representing the design data by unstructured triangular surface meshes; calculating a displacement measure representing local differences between the first and second design modifications; calculating a performance difference between the first and second design modifications, the performance difference represented by at least one criterion; and outputting sensitivity information representing correlation between the displacement measure and the performance differences.