This study examines the process of optimising machining parameters in the turning of EN8 steel. The PROMETHEE-II multi-criteria decision-making technique is utilised for this purpose. The analysed machining variables consist of Material Removal Rate (MRR), Surface Roughness (SR), Acceleration (Ac), and Tool Wear (TW). These variables are influenced by the cutting speed (Vc), Feed Rate (FR), and Depth of Cut (DoC) which serve as input parameters. The experimental trials were performed utilizing Taguchi's L27 orthogonal array on a CNC lathe. The ANOVA analysis showed that Vc had the most substantial effect on MRR, SR, and Ac, whereas FR had the greatest influence on TW. The PROMETHEE-II approach determined that the most favourable machining settings are a cutting speed (Vc) of 200 m/min, an FR of 0.08 mm/rev, and a DoC of 0.2 mm. Given these circumstances, the MRR achieved a value of 2.887 cubic millimetres per second, the SR was minimized to 0.744 micrometres, the Ac was decreased to 0.026 meters per second squared, and the TW was restricted to 0.026 millimetres. The study finds that PROMETHEE-II is a highly successful method for optimizing multiple machining reactions, resulting in substantial enhancements in machining performance.