Quality improvement on Common Rail Type-1 Product using Six Sigma Method and Data Mining on Forging Line in PT. ABC

PT. ABC is a manufacturing company engaged in the automotive sector that produces components of cars and motorcycles. This study aims to improve quality by using the six sigma method with the DMAIC stage (Determine, Measure, Analyze, Improve and Control) and analyze it using data mining techniques. At the definition stage 7 defects were identified Critical To Quality namely pockmarked, burry, dent, rust, lapping, marking and NG marking. The measure DPMO value is 28, 810 and the sigma value is 3, 399. In the analysis phase using data mining with the classification method with the decision tree algorithm, the company's decision in decision-making status of Type 1 Common Rail products agreed on the 10 most interesting parameters. Based on FMEA, it is known as the main cause of the Common Rail Type 1, which is the crust on the dies, marking the product that appears and the trajectory of the heating machine to the forging machine that is too far. The improve phase is using Lifetime Card Dies, the marking is concave inward, reducing the running distance of the heating-forging machine and Controling Check Sheet Product. The DPMO value obtained after improvement is equal to 24095 and the sigma level is 3.476.