Electronic Theses and Dissertation

Ketidakcapaian target produksi pada kegiatan pengangkutan batubara merupakan tantangan serius dalam menjamin keberlanjutan operasional dan rantai pasok batubara (coal supply chain). Banyak penelitian sebelumnya memfokuskan strategi peningkatan produktivitas pada skenario konvensional tanpa mengintegritaskan untuk hambatan (bottleneck) infrastruktur penerimaan di hilir. Penelitian ini dilakukan di PT Mifa Bersaudara, Kabupaten Aceh Barat, Aceh, dan bertujuan untuk menghitung produktivitas aktual alat gali muat (Wheel Loader Komatsu WA900-8) dan alat angkut (Dump Truck 70 ton dan 140 ton), mengevaluasi faktor-faktor penyebab kehilangan produktivitas, serta merumuskan strategi optimalisasi melalui simulasi perbaikan operasional. Data diperoleh melalui pengamatan langsung waktu edar (cycle time), jumlah passing, serta data sekunder berupa timesheet efisiensi kerja alat. Hasil penelitian menunjukkan produktivitas aktual alat muat unit W59002 mencapai 977 ton/jam dan unit W59001 sebesar 963 ton/jam, sementara produktivitas aktual dump truck 70 ton sebesar 29 ton/jam (ketercapaian target 48%) dan dump truck 140 ton sebesar 53 ton/jam (ketercapaian target 48%). Rendahnya produktivitas ini dipengaruhi oleh tingginya waktu antrean di area loading dan dumping, serta rendahnya efisiensi kerja yang baru mencapai 50%. Melalui simulasi gabungan (peningkatan efisiensi kerja 65%, penghilangan antrean, dan optimasi bucket fill factor 100%), produktivitas optimum dapat ditingkatkan menjadi 41,21 ton/jam untuk unit 70 ton dan 75,42 ton/jam untuk unit 140 ton. Selain itu, skenario penambahan hopper 3 direkomendasikan karena terbukti meningkatkan kapasitas area pembongkaran, menekan akumulasi antrean dari 4-5 unit menjadi 2-3 unit saat terjadi hambatan 5 menit, dan mempercepat waktu pemulihan (recovery time) operasional secara signifikan.

The failure to meet production targets in coal hauling activities presents a serious challenge to operational sustainability and the coal supply chain. Previous studies have primarily focused on conventional productivity enhancement strategies without fully integrating bottlenecks in downstream receiving infrastructure. This study was conducted at PT Mifa Bersaudara, West Aceh Regency, Aceh, aiming to calculate the actual productivity of loading equipment (Wheel Loader Komatsu WA900-8) and hauling equipment (Dump Trucks 70 tons and 140 tons), evaluate factors causing productivity loss, and formulate optimization strategies through operational improvement simulations. Data were obtained through direct observation of cycle time, number of passings, and secondary data from equipment work efficiency timesheets. The results showed that the actual productivity of loading equipment unit W59002 reached 977 tons/hour and unit W59001 was 963 tons/hour, while the actual productivity of 70-ton dump trucks was 29 tons/hour (48% target achievement) and 140-ton dump trucks was 53 tons/hour (44% target achievement). This low productivity was driven by high queuing times in the loading and dumping areas, as well as low work efficiency, which only reached 50%. Through a combined simulation (increasing work efficiency to 65%, eliminating queues, and optimizing the bucket fill factor to 100%), optimum productivity could be increased to 41.21 tons/hour for the 70-ton units and 75.42 tons/hour for the 140-ton units. Additionally, the scenario of adding a 3rd hopper is recommended as it is proven to expand dumping area capacity, reduce maximum queue accumulation from 4–5 units to 2–3 units during a 5-minute delay, and significantly accelerate operational recovery time.