UPAYA PENGURANGAN CACAT PADA PROSES PENGELASAN DENGAN MENGGUNAKAN METODE SIX SIGMA DAN TRIZ

PT Boma Bisma Indra (BBI) is a national manufacturing company that produces industrial equipment, with one of its main products being pressure vessels for the mining and oil and gas (MIGAS), petrochemical, and electricity sectors. In the six-month production period, defects were found in the pressure vessel welding process with an average welding defect of 7.3% and a sigma level of 3.68, this exceeded the internal quality threshold of 5% and the sigma target of ±4.5, thus triggering rework and delays in delivery. From these problems, an analysis is needed that provides a structured and measurable solution, namely using the Six Sigma method with the application of DMAIC and TRIZ. Based on research at the define stage, 5 types of defects were found that were used as CTQ, namely porosity, slag inclusion, lack of fusion, undercut, and root concavity. Then at the measure stage, the DPMO value was 13117.6 and sigma 3.72. Furthermore, in the analyze stage using the 80/20 Pareto variation, three priorities were obtained, then the cause and effect were mapped using a fishbone diagram, and analyzed using FMEA which obtained the three highest RPNs, namely contaminated electrodes with, weather disturbances with, and no independent gas flow verification at the tip of the torch. Then in the improve stage, a proposal was made based on the highest RPN obtained using the TRIZ method. In the final stage, namely control, recommendations for improvements were provided based on TRIZ to reduce defects in the welding process results