ANALISIS PENGENDALIAN KUALITAS PRODUK WAJAN ALUMINIUM MENGGUNAKAN METODE SEVEN TOOLS DI CV. SP ALUMINIUM

Abstrak

1. SP Aluminium merupakan perusahaan manufaktur di Yogyakarta yang bergerak dalam bidang pengecoran aluminium untuk memproduksi berbagai peralatan rumah tangga sesuai permintaan pelanggan. Permasalahan yang dihadapi perusahaan adalah tingginya tingkat cacat pada produk wajan Super Merah No.10, yang menimbulkan kerugian material, pemborosan waktu, dan ketidakmampuan memenuhi seluruh pesanan pelanggan. Penelitian ini bertujuan mengidentifikasi jenis cacat dominan, menganalisis akar penyebabnya, serta merumuskan rekomendasi perbaikan menggunakan metode Seven Tools, yang meliputi check sheet, histogram, diagram Pareto, stratifikasi, scatter diagram, peta kendali p, dan diagram sebab-akibat (fishbone). Data dikumpulkan melalui observasi langsung, wawancara, dan dokumentasi hasil inspeksi kualitas selama periode Mei–Juli 2025. Hasil penelitian menunjukkan bahwa dari total produksi sebanyak 7.259 unit ditemukan proporsi cacat rata-rata sebesar 12,9%, dengan cacat berlubang sebagai jenis cacat paling dominan (75% dari total cacat), diikuti cacat pecah (20%) dan cacat berpori (5%). Analisis peta kendali menunjukkan proses secara umum berada dalam batas kendali statistik, meskipun ditemukan beberapa titik yang mendekati batas atas, mengindikasikan variasi proses yang masih perlu dikendalikan. Diagram sebab-akibat mengungkap bahwa faktor metode kerja dan mesin menjadi penyebab dominan cacat berlubang, sedangkan cacat pecah dan berpori masing-masing dipengaruhi oleh ketidakstabilan tekanan mesin serta kualitas material. Penelitian ini merekomendasikan standarisasi prosedur pembersihan cetakan, peningkatan kestabilan mesin press, serta pengendalian kualitas bahan baku sebagai langkah prioritas perbaikan
2. SP Aluminium is a manufacturing company in Yogyakarta engaged in aluminum casting to produce various household appliances according to customer orders. The company faces a persistently high defect rate in its Super Merah No.10 cookware, resulting in material losses, wasted time, and an inability to fulfill customer demand in full. This study aims to identify the dominant defect types, analyze their root causes, and formulate improvement recommendations using the Seven Tools method, comprising check sheets, histograms, Pareto diagrams, stratification, scatter diagrams, p-control charts, and cause-and-effect (fishbone) diagrams. Data were collected through direct observation, interviews, and quality-inspection documentation over the May–July 2025 period. The results show that out of 7,259 units produced, the average defect proportion reached 12.9%, with perforation defects as the most dominant type (75% of total defects), followed by cracking (20%) and porosity (5%). Control chart analysis indicated that the process was generally within statistical control, although several points approached the upper control limit, suggesting process variation that still requires attention. The fishbone analysis revealed that work-method and machine factors were the dominant causes of perforation defects, while cracking and porosity were respectively influenced by unstable press pressure and material quality. This study recommends standardizing mold-cleaning procedures, improving press-machine stability, and tightening raw-material quality control as priority improvement actions.