This is supposed to represent a 4 discipline design problem, and the blue box in the midst of the green boxes is to represent an internal mathematical programming problem called "multidisciplinary analysis or MDA" that reconciles the disciplines involved before the various merit measures of a given design can be calculated.

Right now, simple iteration is most often used, and it is accepted that more sophisticated and robust Newton methods will be needed. This requires a determination of the sensitivities of the results of these simulations with respect to their input parameters.

As I begin my concluding remarks, I have one more new point to make.