The Peruvian cement industry faces notable productivity pressures: current Overall Equipment Effectiveness (OEE) averages around 65.6%, below the worldclass benchmark of 85%; national dispatches declined 1.3% in April 2025, with production falling 1.6% year on year (OEE, ASOCEM). Additionally, defect rates can reach 7.5% in bagging operations (Shesarina et al., 2022). To address these and reduce waste encompassing excess inventory, waiting, and defects the study applied Lean Manufacturing and Six Sigma in the packaging and dispatch stages of a Portland cement plant. Using Value Stream Mapping (VSM), key bottlenecks were identified. Interventions included Kanban for inventory control, SMED to reduce changeover time by 60%, and DMAIC to structure improvements. Implementation resulted in a 50.2% reduction in defective bags (from 4,666 to 2,324 per shift), a 167-minute decline in truck processing time, and dispatch capacity increased from 7 to 10 trucks per shift. Dispatch inventory dropped by over 40%, while OEE improved significantly. Economically, operational costs fell by 18%, achieving ROI in just 1.59 months. These findings demonstrate how integrated Lean Six Sigma tools can markedly boost operational efficiency, quality, and sustainability in the cement sector, closing the OEE gap and responding to declining sectoral performance.