Analysis Of LPG Tank Defect Control Using the Six Sigma Method at Pt. Metal Hitech Engineering
DOI:
https://doi.org/10.21111/at.v11i2.15682Keywords:
Six Sigma, Quality Control, Welding, C-Chart, Quality Costs.Abstract
Quality control in the welding process plays an important role in ensuring product quality and production cost efficiency. This study aims to analyse the defect rate, process performance, and effectiveness of the Six Sigma method in welding quality control at PT Metal Hitech Engineering. The research data was obtained from radiographic inspection results during the period 2024–2025. The research methods used included calculating Defects Per Million Opportunities (DPMO) and sigma levels to measure process capability, analysing process stability using C-Chart control charts, identifying defect causes through cause-and-effect diagrams (fishbone diagrams), and analysing quality costs and sigma level interpolation as a basis for improvement planning. The results of the study show that the quality control system implemented by the company is still reactive and focuses on final inspection, so it is not yet able to prevent defects from occurring at the beginning of the production process. The dominant types of welding defects include incomplete fusion, incomplete penetration, porosity, and undercut. Process performance measurements show a sigma level of 3.94 in 2024 and 3.84 in 2025, indicating that process capability is in the intermediate category. Control chart analysis shows that the process is still within statistical control limits, but there are observation points approaching the upper control limit. Interpolation results indicate that an increase in the sigma level has the potential to significantly reduce the number of defects and repair costs.References
Adiguna, B., Kartawidjaja, A., & Sukwadi, R. (2024). Optimasi Kualitas Pengelasan Dinding Tangki: Pendekatan Six Sigma dan FMEA. Integrasi: Jurnal Ilmiah Teknik Industri, 9(2), 148–161. https://doi.org/10.32502/integrasi.v9i2.206
Afeyokalo. B., Ismail, B., Osheyor, J., Izuchukwu, J., Adepoju, A., & Ninduwezuor, N. (2023). REVIEW ON NON-DESTRUCTIVE TECHNIQUES FOR EARLY FLAW DETECTION IN INSPECTIONS. Materials & Corrosion Engineering Management, 4(2), 44–50. https://doi.org/10.26480/macem.02.2023.44.50
Amalliyah, N., & Nugraha, I. (2025). Analisis Pengendalian Kualitas Hasil Pengelasan Bengkel Welding HO & AO di PT. A Menggunakan Metode Six Sigma dan New Seven Tools. https://jurnal.utb.ac.id/index.php/indstrk
Arief, Z., & Faritsy, A. (2025). Peningkatan Kualitas Produk dengan Menggunakan Metode Six Sigma Di PT Rubber Pan Java. Jumantara Jurnal Manajemen Dan Teknologi Rekayasa, 4(2), 71. https://doi.org/10.28989/jumantara.v4i2.2840
Armijal, Herryandie, A., & Maharani, R. (2023). Analisis Pengendalian Kualitas pada Proses Pembuatan Tangki Dalam Modular Pertashop Menggunakan Metode Seven Tools.
Dwiyanti, N., & Valentin, A. (2025). ANALISIS PENGENDALIAN KUALITAS DENGAN PENERAPAN METODE SIX SIGMA PADA PRODUK RAK GUDANG DI PT.BARMAG RACKING INDONESIA. https://ejournal.up45.ac.id/index.php/jtim
Fadhilah, A., & Dzulquarnain, A. H. (2025). Pengaruh Total Quality Control (TQC) dan Total Quality Management (TQM) Terhadap Kinerja Karyawan pada Penerapan Keselamatan dan Kesehatan Kerja (K3) Sebagai Mediasi: Studi pada Pekerja Bagian Produksi PT. Metal Hitech Engineering. 6, 968.
Fakhri, I. M. (2025). Penerapan Metode Six Sigma dan Lean Six Sigma untuk Pengendalian Kualitas dan Peningkatan Efisiensi di Industri Manufaktur. 4(1).
Fandi Ahmad. (2019). SIX SIGMA DMAIC SEBAGAI METODE PENGENDALIAN KUALITAS PRODUK KURSI PADA UKM. JISI: Jurnal Integrasi Sistem Industri, 6(1), 11–17. https://doi.org/10.24853/jisi.6.1.11-17
Faseela, Sreechitra, & Sherin. F. (2024). Pengujian Non-Destruktif dalam Teknik. International Journal for Research in Applied Science and Engineering Technology, 12(11), 2193–2201. https://doi.org/10.22214/ijraset.2024.65577
Hasan, F., & Muhammad, K. (2022). PENGENDALIAN KUALITAS PRODUK DI PT. PADMA SOODE INDONESIA PADA DIVISI PLASTIC INJECTION DENGAN PENDEKATAN SIX SIGMA. 3(1).
Huda, A., & Widiyanesti, S. (2018). Analisis Pengendalian Kualitas Proses Pengelasan (Welding) Dengan Pendekatan Six Sigma Pada Proyek PT. XYZ. www.jurnal.uniga.ac.id
Ikhsan, M., Pusporini, P., & Rizqi, A. (2021). ANALISIS PENGENDALIAN KUALITAS PRODUK FLAT BAR DENGAN METODE SIX SIGMA PADA PT. JATIM TAMAN STEEL. 2(3).
Mohammad Rian Alfarisy, & Abi Hanif Dzulquarnain. (2023). Implementasi Metode Six Sigma untuk Mengurangi Produk Cacat pada Produk Garam Halus Yodium. Journal of Trends Economics and Accounting Research, 4(2), 548–562. https://doi.org/10.47065/jtear.v4i2.1108
Oktarin, S., & Susanto, N. (2015). ANALISIS SIX SIGMA UNTUK PENINGKATAN KUALITAS PRODUK LINE 28 DEPARTEMEN SEWING DI PT. APPAREL ONE INDONESIA.
Pasaribu, N., Hasibuan, H., Oka, A., & Amelia, J. (2025). Pengaruh Sistem Manufaktur Berkelanjutan terhadap Daya Saing Perusahaan Industri di Indonesia. Mars : Jurnal Teknik Mesin, Industri, Elektro Dan Ilmu Komputer, 3(3), 177–221. https://doi.org/10.61132/mars.v3i3.865
Suwanda. (2024). The role of the six sigma method in controlling and improving product quality. https://doi.org/10.58471/esaprom.v3i01
Terek, M. (2023). How to Estimate the Sigma Level of the Process. Quality Innovation Prosperity, 27(3), 126–140. https://doi.org/10.12776/QIP.V27I3.1947
