A method for generating semiconductor device model parameters includes receiving semiconductor device performance data of statistical instances of semiconductor devices, for a plurality of coordinates in a process space with dimensions of process-dependent device parameters Model parameters are extracted to produce individual model instances, each corresponding to the respective statistical instances for the coordinates in the process space. Statistics of the extracted model parameters are modeled by processing the individual model instances to determine, for each coordinate in the process space, moments describing non-normal marginal distributions of the extracted model parameters and correlations between the extracted model parameters. Semiconductor device model parameters are generated for use in simulating a circuit using the determined moments and the determined correlations, for a selected coordinate in the process space.