One embodiment of the present invention provides a system that identifies an area in a mask layout which is likely to cause manufacturing problems due to a missing or an improperly placed assist feature. During operation, the system receives an uncorrected or corrected mask layout. The system then dissects the mask layout into segments. Next, the system identifies a problem area associated with a segment using a process-sensitivity model which can be represented by a multidimensional function that captures process-sensitivity information. Note that identifying the problem area allows a new assist feature to be added or an existing assist feature to be adjusted, thereby improving the wafer manufacturability. Moreover, using the process-sensitivity model reduces the computational time required to identify the problem area.