In an embodiment of a method of evaluating robustness of a proposed solution to a constraint problem, operational output data for at least first and second modified versions of the proposed solution is generated. The first modified version has at least one control variable of the proposed solution perturbed in a first direction and the second modified version has the at least one control variable of the proposed solution perturbed in a second direction. At least a portion of the generated operation output data is then presented such as on a graphical user interface.