Perancangan Kebijakan Persediaan Material Spare Part Consumable di PT Smelting

Faizulhaq, Arkan Muhammad (2026) Perancangan Kebijakan Persediaan Material Spare Part Consumable di PT Smelting. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

PT Smelting mengelola ratusan material spare part consumable dengan karakteristik nilai, tingkat pergerakan, pola permintaan, dan tingkat kekritisan yang berbeda. Namun, kebijakan persediaan yang diterapkan masih relatif seragam serta menggunakan titik pemesanan kembali berdasarkan pertimbangan historis dan kuantitas pemesanan berdasarkan rata-rata konsumsi enam bulan sebelumnya. Kondisi tersebut berpotensi menyebabkan ketidakseimbangan antara biaya persediaan dan tingkat ketersediaan material. Penelitian ini bertujuan mengklasifikasikan material, merancang kebijakan pengendalian persediaan, mengevaluasi kebijakan usulan melalui simulasi, serta membandingkan pola permintaan pengguna dengan estimasi konsumsi aktual. Klasifikasi dilakukan terhadap 497 material menggunakan metode ABC, FMSN, dan ADI–CV. Klasifikasi VED berdasarkan expert judgment digunakan untuk menetapkan target service level sebesar 90%, 95%, dan 99%. Berdasarkan hasil klasifikasi, dipilih 10 material kategori A untuk dianalisis menggunakan kondisi eksisting, kebijakan continuous review (s, Q), continuous review (s, S), dan periodic review (R, S). Kinerja kebijakan dievaluasi melalui simulasi Monte Carlo selama 52 minggu berdasarkan total biaya persediaan, service level, dan rata-rata persediaan, kemudian dilanjutkan dengan analisis sensitivitas. Hasil penelitian merekomendasikan kebijakan continuous review (s, Q) untuk tujuh material dan kebijakan continuous review (s, S) untuk tiga material. Hasil simulasi menunjukkan bahwa kebijakan terpilih mampu memenuhi target service level seluruh material dan berpotensi menurunkan total biaya persediaan agregat dari Rp22,06 miliar menjadi Rp15,06 miliar atau sebesar 31,73%. Perbandingan pola permintaan menunjukkan bahwa estimasi konsumsi aktual tidak selalu menghasilkan biaya yang lebih rendah karena dipengaruhi oleh variasi permintaan, lead time, nilai material, dan parameter pemesanan. Material 40813063 menunjukkan indikasi internal bullwhip effect, dengan rasio varians permintaan pengguna terhadap estimasi konsumsi aktual sebesar 6,73 akibat praktik order batching. Hasil penelitian menunjukkan bahwa kebijakan persediaan perlu dibedakan berdasarkan karakteristik dan tingkat kekritisan setiap material.
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PT Smelting manages hundreds of consumable spare-part materials with different values, movement rates, demand patterns, and criticality levels. However, the existing inventory policy is relatively uniform, with reorder points determined primarily from historical considerations and order quantities based on the average consumption of the previous six months. This condition may lead to an imbalance between inventory costs and material availability. This study aims to classify the materials, design inventory control policies, evaluate the proposed policies through simulation, and compare user request patterns with estimated actual consumption. A total of 497 materials were classified using ABC, FMSN, and ADI–CV methods. VED classification based on expert judgment was used to establish service level targets of 90%, 95%, and 99%. Based on the classification results, ten category A materials were selected and evaluated under the existing policy, continuous review (s, Q), continuous review (s, S), and periodic review (R, S). Policy performance was evaluated using a 52 week Monte Carlo simulation based on total inventory cost, service level, and average inventory, followed by sensitivity analysis. The results recommend the continuous review (s, Q) policy for seven materials and the continuous review (s, S) policy for three materials. The simulation results indicate that the selected policies satisfy the service-level target for all materials and potentially reduce the aggregate total inventory cost from IDR 22.06 billion to IDR 15.06 billion, representing a reduction of 31.73%. The comparison of demand patterns shows that estimated actual consumption does not always result in lower inventory costs because the outcome is influenced by demand variability, lead time, material value, and ordering parameters. Material 40813063 indicates an internal bullwhip effect, with a variance ratio of user requests to estimated actual consumption of 6.73 due to order batching. These findings demonstrate that inventory policies should be differentiated according to the characteristics and criticality of each material.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	Continuous Review (s, Q), Continuous Review (s, S), Klasifikasi Material, Pengendalian Persediaan, Periodic Review (R, S), Simulasi Monte Carlo, Spare Part Consumable.
Subjects:	H Social Sciences > HD Industries. Land use. Labor > HD55 Inventory control
Divisions:	Faculty of Industrial Technology and Systems Engineering (INDSYS) > Industrial Engineering > 26201-(S1) Undergraduate Thesis
Depositing User:	Arkan Muhammad Faizulhaq
Date Deposited:	28 Jul 2026 04:08
Last Modified:	28 Jul 2026 04:08
URI:	http://repository.its.ac.id/id/eprint/138395

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