A device and technique for monitoring the quality of a manufacturing process, a resulting part or both includes determining a cumulative deviation of an actual process signature from an expected signature. A disclosed example includes determining a quantitative value of a difference between the signatures at each of a plurality of corresponding segments of the signatures. A cumulative deviation based upon deviations of the corresponding segments provides an indication of quality. A disclosed example includes determining a negative cumulative deviation, a positive cumulative deviation and a total cumulative deviation, each of which may be used independently for analysis purposes.