In machining, there exist different quality characteristics that define overall process quality. These quality characteristics are controlled by different input process parameters. Thus, for best possible process quality, optimization is required. The resultant quality characteristics have different weightage of preference depending upon the requirements of the individuals or group. If in a group, the individuals have conflicting interests, it becomes difficult to take decisions. In this article, a new hybrid approach for multi-criteria optimization has been proposed based on the user’s opinion/preference while defining quality characteristics. Accordingly, the new technique may be termed as ‘User’s Preference Rating’ method for optimization. The major advantage of this method is that any number of opinions of the individuals can be considered for calculating the weights. Furthermore, in this technique, it is not essential to specify relationship between all quality characteristics. The implementation of the technique has been illustrated using data during ultrasonic machining of titanium.