Penelitian ini bertujuan untuk mengidentifikasi jenis cacat yang ditemukan serta menganalisis penerapan pengendalian mutu pada proses pemotongan, perataan, dan pembelahan produk barecore di PT Bangun Tata Nusantara, Magetan. Penelitian dilaksanakan selama 30 hari kerja pada bulan Februari sampai April 2026. Pengumpulan data dilakukan melalui observasi, wawancara, dan dokumentasi. Data cacat produk dianalisis menggunakan metode seven tools yang terdiri atas check sheet, defect concentration diagram, pareto diagram, scatter diagram, control chart, histogram, dan fishbone diagram.
Hasil penelitian menunjukkan bahwa jumlah cacat tertinggi terjadi pada proses pembelahan sebanyak 809 cacat dari 3.000 sampel (27%), diikuti proses perataan sebanyak 516 cacat (17%), dan proses pemotongan sebanyak 146 cacat (5%). Jenis cacat yang dominan pada proses perataan dan pembelahan adalah pelos besar. Hasil control chart menunjukkan bahwa proses pemotongan, perataan, dan pembelahan belum terkendali secara statistik karena masih terdapat beberapa titik yang cenderung naik atau turun secara berturut-turut dan beberapa titik yang berada di luar batas kendali atas (Upper Control Limit/UCL) atau batas kendali bawah (Lower Control Limit/LCL). Berdasarkan analisis fishbone diagram, faktor dominan penyebab cacat pada ketiga proses adalah kondisi bahan baku yang tidak seragam dan kondisi mesin yang belum optimal. Selain itu, masih dilakukannya rework pada sebagian output proses perataan dan pembelahan menunjukkan bahwa proses produksi masih memerlukan tambahan waktu, energi, dan biaya sehingga belum berjalan secara efektif dan efisien.
Berdasarkan hasil penelitian, pengendalian mutu pada PT Bangun Tata Nusantara perlu ditingkatkan dengan memprioritaskan perbaikan pada faktor bahan baku dan mesin agar proses produksi dapat berjalan lebih efektif dan efisien.
This study aimed to identify the types of defects and analyze the implementation of quality control in the cutting, planing, and ripping processes of barecore production at PT Bangun Tata Nusantara, Magetan. The research was conducted for 30 working days from February to April 2026. Data were collected through observation, interviews, and documentation. Product defect data were analyzed using the Seven Tools method, consisting of check sheets, defect concentration diagrams, Pareto diagrams, scatter diagrams, control charts, histograms, and fishbone diagrams.
The results showed that the highest number of defects occurred in the ripping process, with 809 defects out of 3,000 samples (27%), followed by the planing process with 516 defects (17%) and the cutting process with 146 defects (5%). The dominant defect in the planing and ripping processes was curved edge defect. Control chart analysis indicated that the cutting, planing, and ripping processes were not statistically under control because several points showed consecutive upward or downward trends, and several points fell outside the Upper Control Limit (UCL) or Lower Control Limit (LCL). Based on the fishbone diagram analysis, the dominant factors causing defects in all three processes were non-uniform raw material conditions and suboptimal machine conditions. In addition, the presence of rework on some outputs from the planing and ripping processes indicated that the production process still required additional time, energy, and costs, resulting in a process that had not yet operated effectively and efficiently.
Based on the results of this study, quality control at PT Bangun Tata Nusantara needs to be improved by prioritizing corrective actions related to raw materials and machinery in order to achieve a more effective and efficient production process.
Kata Kunci :
Kata Kunci: Barecore, Pengendalian Mutu, Seven Tools, Cacat Produk, Statistical Quality Control
