Analysis of N19 product quality control in the PTED process using the Six Sigma DMAIC method (Case Study: X Ltd)

X Ltd. (name changed) is an automotive company facing product defects in the painting process using the electrodeposition painting method on the N19 product, particularly in the PTED area. From May to September 2023, 123 defective units were identified, with defect types including stains (47%), roughness (24%), dirt (19%), and cissing (11%). The DPMO value was 24,651.2, and the sigma level was 2.28. Stain defects were the primary focus due to their high percentage. Analysis revealed that the main cause of stain defects was the lack of inspection methods in areas prone to defects. To address this issue, the study applied the Six Sigma DMAIC method to identify and eliminate the root causes of the defects. The proposed improvement includes revising the method by adding an inspection task in areas likely to cause stain defects. This step is expected to enhance product quality, improve the production process, and reduce downtime caused by frequent repairs.