A computer-based method for defining a surface of a part for placement adjacent a mating surface of a base part is described. The method includes receiving raw data which defines the mating surface of the base part, smoothing the raw data, generating a stable reference frame consisting of at least one of a substantially smooth curve and surface based on the smoothed raw data, calculating a dimensional offset curve or surface using the smoothed raw data and the stable reference frame curve or surface by referencing any peaks in the smoothed raw data within a predefined range of a corresponding point in the stable reference frame curve or surface, smoothing the dimensional offset curve or surface, and outputting the dimensional offset curve or surface for utilization in fabricating the part that is to be adjacent the base part.