Response to Michel, Kleijnen and Permut

Professors Michel and Permut have identified an important application of metamodels. Metamodels may be used to determine the need for accuracy in a forecasting model that provides input to a decision model.

This suggests an interesting possibility—an analyst may wish to construct a metamodel of the forecasting model as well. This metamodel can be combined with the metamodel of the decision model (using the chain rule of differential calculus) to provide a single metamodel for the complex of models.