Electronic Theses and Dissertation

Terdapat beberapa permasalahan pada sistem refueling yang saat ini diterapkan di PT Amman Mineral Nusa Tenggara. Hal tersebut adalah frekuensi refueling yang lebih dari satu kali dalam sehari; terdapat refueling yang melebihi expected time yaitu 17 menit; refueling dilakukan dengan tidak mengoptimalkan kapasitas tangki; dan refueling dilakukan ketika sisa bahan bakar di tangki haul truck masih lebih dari cukup untuk beroperasi. Permasalaham-permasalahan tersebut dapat mengurangi ready hours atau menambah delay hours. Idealnya semakin sedikit delay hours, maka akan semakin banyak ready hours. Alhasil produksi juga akan meningkat dan begitu pula sebaliknya. Berdasarkan permasalahan yang ada maka perlu dilakukan optimalisasi terhadap sistem refueling. Penelitian ini dilakukan dengan menghitung fuel gauge minimum yang dibutuhkan oleh CAT untuk melakukan perjalanan dari lokasi dumping menuju fuel station. Setelah itu dihitung optimum hours dan produksi yang dapat diperoleh CAT 793 setelah sistem refueling dioptimalkan. Perhitungan dilakukan dengan membandingkan 6 skenario menggunakan simulasi Monte Carlo. Tiap skenario dibedakan berdasarkan threshold fuel gauge dan delay pada saat pengisian bahan bakar. Berdasarkan hasil perhitungan didapatkan fuel gauge minimum yang paling banyak adalah 5,2% dari kapasitas tangki yang digunakan. Rata-rata optimum hours yang paling tinggi ialah 21,22 jam dan rata-rata produksi yang paling tinggi ialah 6.930,4 ton. Hasil tersebut didapatkan dari perhitungan pada skenario 2 dengan threshold fuel gauge 10% dan delay 12-14 menit. Sementara itu, rata-rata optimum hours terendah ialah 18,7 jam dan rata-rata produksi yang paling rendah ialah 6.104,9 ton. Hasil tersebut didapatkan dari perhitungan pada skenario 5 dengan threshold fuel gauge 20% dan delay 15-17 menit.

There are several problems with the refueling system currently implemented at PT Amman Mineral Nusa Tenggara. This is a refueling frequency that is more than once a day; there is refueling that exceeds the expected time, namely 17 minutes; refueling is carried out without optimizing tank capacity; and refueling is carried out when the remaining fuel in the haul truck tank is still more than enough to operate. These problems can reduce ready hours or increase delay hours. Ideally, the fewer delay hours, the more ready hours there will be. As a result, production will also increase and vice versa. Based on existing problems, it is necessary to optimize the refueling system. This research was carried out by calculating the minimum fuel gauge required by CAT to travel from the dumping location to the fuel station. After that, the optimum hours and production that can be obtained by CAT 793 after the refueling system is optimized are calculated. Calculations were carried out by comparing 6 scenarios using Monte Carlo simulation. Each scenario is differentiated based on the fuel gauge threshold and delay during refueling. Based on the calculation results, the maximum minimum fuel gauge is 5.2% of the tank capacity used. The highest average optimum hours was 21.22 hours and the highest average production was 6,930.4 tons. These results were obtained from calculations in scenario 2 with a fuel gauge threshold of 10% and a delay of 12-14 minutes. Meanwhile, the lowest average optimum hours was 18.7 hours and the lowest average production was 6,104.9 tons. These results were obtained from calculations in scenario 5 with a fuel gauge threshold of 20% and a delay of 15-17 minutes.