Quality Control of Gravity Roller Conveyor Products Using an Integrated DMAIC and Kaizen Method at PT. Surya Gemilang Buana

Abstract

In the face of increasingly competitive conditions in the manufacturing industry, companies are required to consistently maintain product quality, including the gravity roller conveyor products manufactured by PT. Surya Gemilang Buana, where various quality problems were still identified during the period from August to October 2024. This condition has led to decreased production process efficiency and increased operational costs. This study aims to control and improve product quality through the implementation of the DMAIC (Define, Measure, Analyze, Improve, Control) method integrated with Kaizen. The results show that out of a total production of 3,055 units, 348 units were defective. The most dominant defect was dimensional inaccuracy, with 141 units (40.5%), followed by scratch defects totaling 119 units (34.2%) and surface roughness defects amounting to 88 units (25.3%). With three defect opportunities per unit, the Defects Per Million Opportunities (DPMO) value was calculated at approximately 37,960. This DPMO value corresponds to a process sigma level of approximately 3.27 sigma, indicating that the process capability remains at a moderate level and has not yet reached optimal performance. Based on the findings, it can be concluded that the quality control system in the gravity roller conveyor production process still requires improvement. Human factors, work methods, and machine conditions are the dominant causes of defects. Therefore, the consistent implementation of continuous improvement through DMAIC and Kaizen is expected to reduce defect rates and enhance the overall production quality of the company.