This study proposes the importance of process parameters in improving the surface roughness of aluminum alloy 6061 by developing a hybrid framework integrating Design of Experiments (DOE) and Six Sigma methodologies. Alloy-6061 is a common component used in many small and medium-sized enterprises (SMEs) to manufacture high-quality aerospace parts and sensitive industrial products. Implementing this hybrid framework improves key machining metrics and overall equipment effectiveness that align with strict supplier quality requirements from leading aerospace firms and enhances bottom-line results. Using a Taguchi L9 orthogonal array and regression models within the DMAIC (Define-Measure-Analyze-Improve-Control) cycle, this study identified optimal turning parameters—insert radius, feed rate, and depth of cut—for minimizing surface roughness. Results indicate that feed rate is the most influential factor, followed by insert radius and depth of cut. DMAIC methodology is a fundamental quality improvement strategy that enables young professionals to address surface roughness improvement in final products. Practitioners can adapt the proposed integrated methods to different project-based quality enhancement challenges.