ANALISIS EFEKTIVITAS MESIN RIBBON MIXER MENGGUNAKAN METODE OVERALL EQUIPMENT EFFECTIVENESS (OEE) UNTUK MENINGKATKAN PRODUKTIVITAS DI PT POLOWIJO GOSARI GROUP

Mesin Ribbon Mixer merupakan salah satu mesin utama dalam proses produksi pupuk dolomit di PT Polowijo Gosari Group, karena berfungsi mencampurkan bahan baku hingga mencapai kondisi homogen. Berdasarkan data operasional perusahaan, masih ditemukan unplanned stoppage yang menyebabkan berkurangnya waktu operasi efektif mesin, sehingga berpotensi menurunkan produktivitas proses produksi. Penelitian ini bertujuan untuk menganalisis tingkat efektivitas mesin Ribbon Mixer menggunakan metode Overall Equipment Effectiveness (OEE), mengidentifikasi jenis kerugian dominan melalui analisis Six Big Losses, menelusuri akar penyebabnya menggunakan Root Cause Analysis (RCA) dengan pendekatan Fault Tree Analysis (FTA), serta merumuskan usulan perbaikan untuk meningkatkan efektivitas mesin dan produktivitas produksi. Data yang digunakan meliputi data waktu kerja mesin, downtime, jumlah produksi, dan produk cacat selama periode September 2025 hingga Mei 2026. Hasil penelitian menunjukkan bahwa rata-rata nilai OEE mesin Ribbon Mixer sebesar 75,91%, masih berada di bawah benchmark OEE sebesar 85%, dengan nilai terendah terjadi pada Desember 2025 (50,95%) dan Mei 2026 (56,88%). Performance Rate teridentifikasi sebagai komponen yang paling berpengaruh terhadap penurunan efektivitas mesin, sementara Availability dan Quality Rate relatif stabil. Analisis Six Big Losses menunjukkan bahwa Reduced Speed Losses (59,9%) dan Equipment Failure Losses (29,2%) merupakan dua jenis kerugian dengan kontribusi terbesar, secara kumulatif mencapai 89,2% dari total losses. Hasil FTA mengindikasikan bahwa kedua jenis kerugian tersebut bersumber dari akar penyebab yang sama, yaitu kadar air bahan baku yang tidak terkendali, yang diperparah oleh belum terstrukturnya sistem preventive maintenance dan minimnya pemeriksaan rutin oleh operator. Usulan perbaikan yang dirumuskan meliputi penerapan mesin rotary dryer sebagai alternatif pengendalian kadar air bahan baku, penguatan SOP preventive maintenance, pelatihan operator, serta penggunaan spare part sesuai spesifikasi mesin.
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The Ribbon Mixer machine is one of the main machines in the Dolomite fertilizer production process at PT Polowijo Gosari Group, as it functions to mix raw materials until they reach a homogeneous condition. Based on the company's operational data, unplanned stoppages are still found, which reduce the effective operating time of the machine, thereby potentially decreasing the productivity of the production process. This study aims to analyze the effectiveness level of the Ribbon Mixer machine using the Overall Equipment Effectiveness (OEE) method, identify the dominant types of losses through the Six Big Losses analysis, trace the root causes using Root Cause Analysis (RCA) with a Fault Tree Analysis (FTA) approach, and formulate improvement proposals to enhance machine effectiveness and production productivity. The data used includes machine working hours, downtime, production quantity, and defective products during the period from September 2025 to May 2026. The research results show that the average OEE value of the Ribbon Mixer machine is 75.91%, still below the OEE benchmark of 85%, with the lowest values occurring in December 2025 (50.95%) and May 2026 (56.88%). Performance Rate was identified as the most influential component in the decline of machine effectiveness, while Availability and Quality Rate remained relatively stable. The Six Big Losses analysis shows that Reduced Speed Losses (59.9%) and Equipment Failure Losses (29.2%) are the two types of losses with the largest contributions, cumulatively reaching 89.2% of total losses. FTA results indicate that both types of losses stem from the same root cause, namely the uncontrolled moisture content of raw materials, which is exacerbated by the unstructured preventive maintenance system and the lack of routine inspections by operators. The proposed improvements include the implementation of a rotary dryer machine as an alternative for controlling raw material moisture content, strengthening the preventive maintenance SOP, operator training, and using spare parts according to machine specifications.