Pengendalian Kualitas untuk Menurunkan Defect Tebal Tipis pada Proses Produksi Blowing menggunakan Metode DMAIC di PT XYZ

Abstract

PT XYZ masih menghadapi permasalahan kualitas pada proses produksi blowing, terutama defect tebal tipis yang menjadi penyumbang terbesar terhadap total reject. Penelitian ini bertujuan menganalisis pengendalian kualitas yang diterapkan perusahaan, mengidentifikasi akar penyebab defect tebal tipis, dan menyusun usulan perbaikan dengan metode define, measure, analyze, improve, and control (DMAIC). Data diperoleh dari observasi lapangan, konfirmasi teknis, serta data produksi dan defect periode Mei–Oktober 2025. Hasil penelitian menunjukkan bahwa persentase reject masih berfluktuasi pada kisaran 5,03%–10,37% dan defect tebal tipis mencapai 49,04% dari total reject. Nilai DPMO sebesar 30.039,24 dengan level sigma 3,38 menunjukkan bahwa defect tebal tipis merupakan titik lemah utama proses. Akar masalah utama adalah belum adanya checksheet inspeksi die pin, kriteria penggantian die pin yang terdokumentasi, dan checksheet pengencangan baut parison. Usulan perbaikan meliputi OPL, checksheet inspeksi die pin, checksheet pengencangan baut parison, dan A3 report.

PT XYZ still faces quality problems in the blowing production process, particularly thick-thin defects, which contribute the largest proportion of total rejected products. This study aimed to analyze the company’s quality control practices, identify the root causes of thick-thin defects, and propose improvements using the (DMAIC) method. The study used field observations, technical discussions, and production and defect records from May to October 2025. The results showed that the reject rate fluctuated between 5.03% and 10.37%, while define, measure, analyze, improve, and control thick-thin defects accounted for 49.04% of total rejected products. A DPMO value of 30,039.24 with a sigma level of 3.38 indicated that this defect was the main weakness of the process. The main root causes were the absence of a die pin inspection checksheet, documented die pin replacement criteria, and a parison bolt tightening checksheet. The proposed improvements included an OPL, a die pin inspection checksheet, a parison bolt tightening checksheet, and an A3 report.