The current research demonstrates how Statistical Quality Control and the Six Sigma DMAIC approach can be used to reduce defects in producing pump casings at a pump manufacturing firm. The company had serious quality issues for some time. They were surface finish problems, incorrect dimensions due to excessive grinding, cracking, and bores that were oversized or undersized. All of those resulted in high rejections and rework. Researchers applied the DMAIC steps to address it. That is, Define, Measure, Analyze, Improve, and Control. Which was supported with tools like Pareto charts, Fishbone diagrams, Gage R and R studies, Failure Mode and Effective Analysis (FMEA), and Process Capability analysis. Ultimately, rejections decreased substantially. They dropped from 30 out of 350 casings to 8. The sigma level improved as well. It increased from 2.86 to 3.49 To maintain stability, they implement Kaizen discipline and control mechanisms on the basis of standard operating procedures. In total, the job demonstrates that organized statistical tools actually improve quality and efficiency in the manufacture of pumps.