Usulan perbaikan kualitas komponen overflow pada produk asphalt mixing plant dengan menggubakan metode six sigma di PT Bukaka Teknik Utama
P PT. Bukaka Teknik Utama bergerak dalam bidang konstruksi, alat — alat berat, transportasi, teknik, industri telekomunikasi, dan bidang sarana pekerjaan umum. Road Construction Equipment (RCE) merupakan salah satu dan unit usahanya. RCE memproduksi macam — macam peralatan konstruksi jalan, salah satunya yaitu Asphalt Mixing Plant (AMP). Berdasarkan data historis perusahaan pada bulan Oktober - Desember 2011, overflow memiliki persentase cacat tertinggi dibanding komponen AMP lainnya yaitu sebesar 6,38 %. Untuk memperbaiki sistem pengendalian kualitas tersebut, perlu diterapkan metode Six Sigma dengan pendekatan DMAIC (Define — Measure — Analysis —Improve — Control) yang berguna untuk mengurangi persentase cacat produk. Tujuan penelitian ini adalah untuk mengidentifikasi dan menentukan proses mana yang memiliki cacat dominan, menganalisa penyebab cacat tersebut dan memberikan usulan perbaikan. Bedasarkan perhitungan nilai DPMO (Defect Per Million Opportunities) pada komponen overflow sebesar 444.000 dengan tingkat sigma sebesar 1,64. Dan diagram pareto diambil tiga cacat terbesar yaitu cacat retak bor 22,8 %, cacat kelupas 21,1 % dan cacat baret 17,5 %. Untuk meningkatkan tingkat sigma, dilakukan analisa perbaikan proses produksi menggunakan metode Failure Mode and Effect Analysis (FMEA) untuk mengetahui faktor penyebab kegagalan, kemudian menghitung nilai RPN tertinggi sebagai prioritas penanganan masalah. Usulan perbaikan dilakukan pada proses drilling dan painting. Karena sebagian besar penyebab kecacatan disebabkan oleh faktor manusia, maka usulan perbaikan untuk kedua proses tersebut adalah membuat Working Instruction (WI), diharapkan agar operator yang bekerja dapat lebih teratur dan disiplin mengikuti urutan proses pengerjaan yang benar.
P PT. Bukaka is running in construction, Heavy Equipment transportation, engineering, and the general public works facilities. Road Construction Equipment (RCE) is one of their business unit. Road Construction Equipment business unit manufactures many kind of road construction equipment, and one of their .product is Asphalt Mixing Plant (AMP). Based on the company history research during October — December 2011, overflow component on Asphalt Mixing Plant (AMP) is the highest percentage of defect than the other components in Asphalt Mixing Plant is for about 6,38%. To improve the quality control system, the company need a method to approach six sigma DMAIC (Define —Measure — Analysis — Improve — Control) which useful for reducing the percentage of defective product. The purposes of this study is to identify and determine which of the process which has the dominant defect, analyze the causes of defects and provide the proposed improvements. Based on the DPMO (Defect per Million Opportunities) Calculation in overflow component obtained from the result of the calculation is about 444.000 with six sigma level is 1,64. Based on Pareto Diagram we are taken 3 most highest defect are drill cracks 22,8%, exfoliate defect 21,1% and beret defect 17,5%. To generate sigma level, We are making improvement analyze in production process using Failure Mode and Effect Analysis (FMEA) method to know the failure factor caused, by than we calculating the highest RPN value as a priority in handling defect caused. The proposed improvements are made in the process of drilling and painting, since some of the defect factor is caused by human error, therefore the proposed improvements for the two working process is making Working Instruction (WI), with providing the Working Instruction we are expected that the operator can be more organized and disciplined to follow the correct sequence of work processes.