Editing Multidisciplinary design optimization (section)

===Constraints===
A constraint is a condition that must be satisfied in order for the design to be feasible. An example of a constraint in aircraft design is that the [[lift (force)|lift]] generated by a wing must be equal to the weight of the aircraft. In addition to physical laws, constraints can reflect resource limitations, user requirements, or bounds on the validity of the analysis models. Constraints can be used explicitly by the solution algorithm or can be incorporated into the objective using [[Lagrange multiplier]]s.