1. A computer-implemented method, comprising: storing a representation of elements of a physical structure in a computer aided design (CAD) model; providing the representation of elements to a first analysis program for application of simulated loads to the representation of elements; storing in the CAD model first load information that specifies the simulated loads applied by the first analysis program; providing the representation of elements to a second analysis program for application of simulated loads to the representation of elements; and storing in the CAD model second load information that specifies the simulated loads applied by the second analysis program so that the CAD model includes a history of loads applied by the first and second analysis programs.