This study aims to investigate the consistency between the results obtained from the turning operation. To this end, Ti 6Al-4V alloy workpiece was machined using CNC lathe. In addition, surface roughness (Ra), vibration, and energy consumption values were determined through turning. Experimental results were then analyzed statistically. Response Surface Method (RSM) and grey relational analysis were employed for statistical analysis. According to RSM analysis, grey relational analysis, and ANOVA and regression analysis, the feed rate was found the most e ective parameter that negatively a ects surface roughness, energy consumption, and vibration. Finally, the steps involved in conducting grey relational analysis and the process of obtaining the results were examined.