<![CDATA[This study aims to analyze and implement corrective actions for misrun defects in the casting process of gasoline pistons for hatchback-type vehicles at PT XYZ. During 2024, the company produced approximately 45,000 piston units monthly, with misrun defects accounting for 52.56% of total defects the highest defect category. Specifically, gasoline piston type X contributed 9.84% to the overall misrun rate, significantly impacting production efficiency and material waste. To address this issue, the PDCA (Plan, Do, Check, Action) method was systematically applied using the Eight Steps approach. Root cause identification was conducted through fishbone diagram analysis and 5 Why methodology, revealing issues in mold ventilation, cooling processes, and gas flow direction. The implemented solutions included: (1) addition of extra gas vents on the mold, (2) repositioning of gas vents on the flip core, (3) introduction of a standard operating procedure (SOP) for cooling mold inspection, and (4) modification of the argon gas spray direction. Following these improvements, the misrun defect rate decreased to 5.16%, achieving a reduction effectiveness of 47.5%, which exceeded the company's target of 40%. These results demonstrate that the PDCA method with the Eight Steps approach is effective in reducing defect rates and improving product quality in piston casting processes. Practically, this research provides a replicable framework for defect reduction in precision casting industries, while theoretically, it validates the integration of PDCA with structured problem-solving tools in manufacturing contexts. The reduction translates to decreased material costs, improved delivery schedules, and enhanced customer satisfaction.]]>
