Sustainable manufacturing focuses on increasing productivity by regulating process parameters through resource optimization. Industries are attempting to use fewer resources in machining of any material in order to improve productivity and sustainability. It can be accomplished by higher Material Removal Rate (MRR) and decreased defective components since enhanced MRR requires less energy usage and material waste can be reduced by manufacturing high-quality products. In the drilling operation of rotary ultrasonic machining (RUSM), this study intends to investigate the effects on material removal rate (MRR) by varying the process parameters and overcut, in order to reduce overcut error, which increased the number of faulty parts (RUSM). For this investigation, the Six Sigma (DMAIC) technique was used. Gauge R&R study was conducted to check the accuracy of measuring instrument by ensuring its measurements are repeatable and reproducible followed by cause and effect analysis to find out possible causes for a specific problem. More specifically, the current study focusses on determining the relative effect of process parameters on overcut and MRR by using a full factorial design. Ultrasonic power control factors and feed rate were chosen as the study's control variables. According to the study's findings, the total gauge R&R was 1.78%, which shows that the part-to-part variance is significant for an overcut error. The results revealed that at 0.6 mm/min feed rate and 75% ultrasonic power, the MRR achieved was maximum. With an ultrasonic power of 50% and 0.6mm/min feed rate, the overcut error was reduced. When using the revised machining conditions, the mean overcut error was reduced by 34.18%, which was a significant reduction. It can be concluded that machining with optimized process parameters leads to economically sound processes and solves persistent problems in terms of improved MRR, reduced overcut defects and increased productivity.