Systems and methods for process aware metrology are provided. One method includes selecting nominal values and one or more different values of process parameters for one or more process steps used to form the structure on the wafer, simulating one or more characteristics of the structure that would be formed on the wafer using the nominal values, and determining parameterization of the optical model based on how the one or more characteristics of the structure vary between at least two of the nominal values and the one or more different values.