1. A method, comprising: providing a model for a device parameter of a wafer as a function of first and second process parameters, the device parameter corresponding to an electrical wafer characteristic, and the first and second process parameters corresponding to different physical wafer characteristics, respectively; deriving target values of the first and second process parameters based on a specified target value of the device parameter; performing a first fabrication process on the wafer in response to the target value of the first process parameter; thereafter measuring an actual value of the first process parameter obtained as a result of the first fabrication process; updating the model using the actual value of the first process parameter; deriving a revised target value of the second process parameter using the updated model; performing a second fabrication process on the same wafer in response to the revised target value of the second process parameter; and thereafter measuring an actual value of the device parameter; wherein the updating the model and the deriving the revised target value are performed so that the measured actual value of the device parameter substantially approaches the specified target value of the device parameter.