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Usulan Perbaikan Lingkungan Kerja di Area Produksi Drum Besi CV. Lampung Aspalindo Wahyudi, Rizqi; Abdillah, Zaki; Armadani, Elvi
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Publisher : Universitas Teuku Umar

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Abstract

CV Lampung Aspalindo merupakan suatu badan usaha yang berjalan pada bidang industri manufaktur. Badan usaha ini memproduksi produk drum besi khususnya untuk produk aspal dalam drum dari produk setengah jadi hingga produk yang dapat dijual. Permasalahan perusahaan saat ini ialah belum mengkhususkan perhatiannya kepada kondisi lingkungan kerja, dan tidak ada divisi/sub-divisi yang dikhususkan untuk masalah tersebut. Masalah tempat kerja yang didapati antara lain tidak terdapatnya marker line di daerah pengerjaan produksi seperti area bahan baku, mesin, dan lain-lain. Hal lain yang ditemukan ialah beberapa barang personal pekerja dan peralatan kerja belum memiliki lokasi yang ditentukan. Pekerja di area produksi masih belum memperhatikan kondisi kebersihan dan tidak ada rotasi jadwal tugas pembersihan. Hasil dari penelitian ini adalah penilaian checklist audit di area produksi yang mendapat nilai sebesar 26% dan masuk kategori buruk, maka peluang penerapan 5S di area produksi CV Lampung Aspalindo sangat perlu untuk memperbaiki lingkungan kerja. Berdasarkan nilai evaluasi sebelum perbaikan didapatkan nilai sebesar 35% dan setelah dilakukan implementasi 5S didapatkan nilai sebesar 77%. Terdapat 11 implementasi yang berhasil dilakukan dan terdapat 6 usulan yang diharapkan dapat diimplementasikan di CV Lampung Aspalindo.
Model Pengembangan Kebijakan Inventori Joint Replenishment untuk Multi Produk dengan Mempertimbangkan Produk Substitusi Elvi Armadani; M Zaky Hadi; Dian Fajarika; Juniwati Juniwati; Hersa Dwi Yanuarso
ULIL ALBAB : Jurnal Ilmiah Multidisiplin Vol. 2 No. 8: Juli 2023
Publisher : CV. Ulil Albab Corp

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.56799/jim.v2i8.1963

Abstract

Pendekatan joint replenishment merupakan salah satu metode yang digunakan dalam melakukan replenishment inventori. Dengan joint replenisment. Dengan joint replenishment biaya pesan dapat diminimasi karena hanya menggunakan satu kali pengiriman untuk beberapa produk sekaligus. Contoh proses replenishment inventori yang menggunakan pendekatan ini adalah pada retailer maupun toko grosir dengan jenis produk consumer goods. Ciri dari pasar consumer goods adalah adanya kemungkinan pemenuhan demand dengan produk lain yang sejenis, sehingga dapat dikatakan produk tersebut dapat saling mensubstitusi. Selain itu, terdapat kesulitan dalam proses replenishment produk jenis ini yaitu adanya ketidakpastian demand dari sisi customer. Penelitian ini mengembangkan model inventori Maddah, dkk (2016) mengenai model joint replenishment dengan mempertimbangkan substitusi produk. Pada penelitian ini, digunakan demand dengan sifat probabilistic. Service level telah ditetapkan sebelumnya oleh perusahaan (probabilistic sederhana). Ukuran kinerja yang diperhatikan adalah meminimasi ongkos total yang terdiri dari ongkos pembelian, ongkos pemesanan, ongkos penyimpanan, dan ongkos kekurangan. Berdasarkan uji coba model, didapati hasil bahwa model joint replenishment dengan substitusi memberikan ongkos total lebih rendah dibandingkan tanpa substitusi. Selain itu, model tersebut juga sensitif terhadap perubahan harga dan perubahan ongkos simpan.
Improving Inventory Control in the Electrical Sector Using Forecasting Models: A Comparative Study of ARIMA, Exponential Smoothing, Croston, and SBA Elvi Armadani; Daniel Jeffry; Muhammad As’adi; Yulizar Widiatama
Jurnal Serambi Engineering Vol. 10 No. 2 (2025): April 2025
Publisher : Faculty of Engineering, Universitas Serambi Mekkah

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Abstract

PT. ABC Tarahan Sector is a State-Owned Enterprise that is engaged in services to distribute electricity to the general public. PT. ABC Tarahan Sector distributes about 80% of total electricity consumption in Lampung and 20% is distributed through ABC Palembang. Material planning is one of the most important factors to meet the production targets produced every year. The purpose of this study is to determine the method with the smallest error value based on the time series data available in the company. The data used in this study is the company's material demand data in 2018-2023. The level of accuracy in the forecasting value is determined by looking at the smallest absolute error value in each method. The forecasting results will then be measured based on the value of the service level, inventory level, and inventory cost budget. The existing condition of the company produces an error value of 7.32118, the amount of material is 17,195, the service level is 95.06%, and the warehouse cost is Rp. 36,012,143,757.00. The researcher forecasts using the Arima, Exponential Smoothing, Croston, and Syntetos Boylan Approximation methods. The results of the data analysis resulted in a decrease in the error value of 31.3%, a decrease in the amount of material by 22.38%, an increase in service levels to 95.33%, and a warehouse cost savings of Rp. 182,068,361.00.
Enhancing Supply Chain Performance for Sustainable Development in the Small and Micro Industries The Role of Organizational and Local Culture, Support from Financial Institutions, and Government Revadi, Chindy E; Armadani, Elvi; Siregar, Lina Sari
Journal of Sustainable Economics Vol. 3 No. 1 (2025): Journal of Sustainable Economics
Publisher : TALENTA PUBLISHER UNIVERSITAS SUMATERA UTARA

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32734/jse.v3i1.20549

Abstract

The economic growth potential of North Sumatra is globally recognized due to the achievement of sustainable development goals. This research aims to explore the integration of environmental, social, economic, organizational, local culture, government, and financial institution support factors that can improve supply chain performance and sustainability for small and micro industries in North Sumatra. The study uses a mixed-methods approach that involves in-depth interviews and structured questionnaires to examine the central roles of these factors. The findings underscore the importance of environmental considerations in supply chain management, the impact of local cultural traditions on organizational performance, and the need for innovative economic solutions to improve efficiency and traceability by government and financial support. The research also suggests the implementation of comprehensive policies that integrate all aspects of collaboration to achieve the Sustainable Development Goals in North Sumatra, addressing deglobalization and geopolitical crises.
SOSIALISASI RISIKO LIMBAH MINYAK JELANTAH DAN SOLUSINYA Wahyuni, Fitri; Nisa, Rasya Aulia Nathania; Julian, James; Lumbantoruan, Regina Natalindah; Mahdhudhu, Fathin Muhammad; Purba, Riki Hendra; Armadani, Elvi
Jurnal Bakti Masyarakat Indonesia Vol. 8 No. 1 (2025): Jurnal Bakti Masyarakat Indonesia
Publisher : Lembaga Penelitian dan Pengabdian kepada Masyarakat, Universitas Tarumanagara

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24912/jbmi.v8i1.34381

Abstract

Used cooking oil is cooking oil that is no longer suitable for use because it has undergone changes in physical and chemical properties during the frying process. Used cooking oil is a hazardous and toxic waste; consuming it can cause negative impacts on health and disposing of it carelessly can cause environmental pollution. However, public knowledge about the dangers and impacts of used cooking oil is still minimal. A study showed that there are still many people who dispose of used cooking oil on the ground and waterways. Therefore, the activity designed by the PKM team of Universitas Pembangunan Nasional Veteran Jakarta aims to increase public knowledge about the dangers and impacts of used cooking oil and provide solutions to reduce the pollution of used cooking oil waste. This activity was carried out in the Grand Pakis Residence housing complex using socialization and training methods. In this activity, the PKM team invited representatives from the Jalantara foundation as speakers to explain the impact of used cooking oil on the environment and health to the community. Not only that, the community was also given a training on processing used cooking oil into other products as a solution to reduce used cooking oil waste. The result of this activity is that the knowledge of residents about the dangers of used cooking oil for the environment and health has increased by 80.95%. In addition, the residents also know how to reduce used cooking oil by turning it into useful products such as soap.
Peramalan Jumlah Permintaan Crumb Rubber SIR 20 Menggunakan Metode Backpropagation Pada PT XYZ Tarigan, Andre Otniel; Armadani, Elvi; Wahyudi, Rizqi
JURNAL INTEGRASI Vol. 17 No. 2 (2025): Volume 17, Nomor 2, Oktober 2025
Publisher : Pusat Penelitian dan Pengabdian Masyarakat Politeknik Negeri Batam

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30871/ji.v17i2.7649

Abstract

PT XYZ merupakan industri manufaktur yang memproduksi crumb rubber dengan jenis SIR 20. Tahun 2021, perbandingan jumlah persediaan bahan baku dengan hasil produksi memiliki tingkat eror MAPE lebih dari 50% yang mengindikasikan bahwa model yang digunakan tergolong buruk. Selisih antara jumlah persediaan bahan baku dan jumlah produksi berpotensi meningkatkan biaya produksi. Jumlah persediaan bahan baku di atas titik optimal dapat menyebabkan meningkatnya biaya penyimpanan, sedangan jumlah persediaan di bawah titik optimal berpotensi menambah biaya produksi akibat biaya kekurangan. Tujuan penelitian ini adalah memilih model arsitektur Backpropagation dengan nilai MAPE terendah yang selanjutnya digunakan memprediksi jumlah permintaan produk SIR 20 pada tahun 2023. Arsitektur Backpropagation yang digunakan pada penelitian ini adalah (3-9-1-1), (3-10-1-1), (3-11-1-1), (3-11-1-1), dan (3-12-1-1). Variabel input dalam penelitian ini adalah tahun produksi, jumlah hari, dan harga SIR 20. Model Backpropagation (3-11-1-1) merupakan model yang memberikan hasil prediksi dengan eror terendah, yaitu 14,5%. Model tersebut memberi hasil penuruan nilai MAPE sebesar 36,5% dan peningkatan pendapatan berdasarkan selisih antara pembelian bahan baku dan penjual produk sebesar Rp 62.295.269.963,13.
Numerical investigation of heat reduction system in 42110 Lithium-Ion battery packs using cooling plate spacing variations Adhitama, Bima Rakha; Julian, James; Wahyuni, Fitri; Madhudhu, Fathin Muhammad; Armadani, Elvi
Jurnal Polimesin Vol 23, No 6 (2025): December
Publisher : Politeknik Negeri Lhokseumawe

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30811/jpl.v23i6.7692

Abstract

An efficient thermal reduction system is crucial for ensuring the optimal performance and safety of Electric Vehicle (EV) batteries, notably by maintaining uniform temperature distribution and minimizing the risk of thermal runaway. This study presents a numerical investigation of the thermal behaviour of a liquid-cooled system for a cylindrical Li-ion 42110 battery pack, focusing on the influence of varying cold-plate spacing. Three cold plate configurations with spacing ratios r = 0.78, r = 0.33, and r = 0 were examined, with r = 0.78 corresponding to the most significant separation. The simulation employed a Reynolds-Averaged Navier–Stokes (RANS) model to resolve fluid flow and energy transport, and the heat-generation profile was derived from experimental data. The results show that all cooling configurations substantially reduced the maximum temperature relative to the uncooled case, with the widest spacing (r = 0.78) achieving the most significant average reduction of 19.736%. However, designs with smaller spacing exhibited slightly higher temperatures and reduced uniformity, particularly near the positive pole, where heat concentration is more pronounced. The temperature deviation remained within the acceptable 2% threshold. These findings highlight not only the thermal effectiveness of each spacing ratio but also its design implications, demonstrating that spacing plays a critical role in controlling peak temperature and maintaining uniformity. Overall, the study emphasizes that strategic cold-plate spacing is essential for reliable, efficient, and thermally stable battery operation in EV applications.
The effect of flap thickness on the hydrodynamic performance of an oscillating wave surge converter Julian, James; Nisa, Rasya Aulia Nathania; Wahyuni, Fitri; Purba, Riki Hendra; Madhudhu, Fathin Muhammad; Armadani, Elvi
Jurnal Polimesin Vol 23, No 6 (2025): December
Publisher : Politeknik Negeri Lhokseumawe

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30811/jpl.v23i6.7682

Abstract

With the growing demand for energy and the need to transition to renewable sources, ocean wave energy presents great potential. The Oscillating Wave Surge Converter (OWSC) is a promising technology due to its nearshore applicability, structural simplicity, and robust design. This study systematically investigates the effect of flap thickness on the dynamic performance of a hinge-mounted OWSC using the Boundary Element Method (BEM).   The research models the hydrodynamic interactions and analyzes the effects of three different flap thicknesses on key metrics, including maximum angle deviation, angular velocity, torque, and power capture. The results indicate that all flap variations demonstrate stable oscillatory movement, but greater flap thickness reduces the maximum angle deviation due to increased inertia and hydrostatic pressure. A resonant peak was observed for all thicknesses at a wave period of 1.3 seconds, where energy transfer was maximized. At this frequency, the thickest flap achieved the highest efficiency (78.94%), followed by the intermediate (77.50%) and thinnest (70.77%) variations. The findings suggest that while flap thickness influences efficiency, the primary factor for maximizing energy capture is the alignment of the wave period with the device's natural frequency.
Erosion Behavior of SKD11 Tool Steel Under Different Impact Angles and Particle Velocities: A Finite Element Analysis Study Deva Ihsan Khoirunas; Purba, Riki Hendra; Situmorang, Riky Stepanus; James Julian; Fitri Wahyuni; Elvi Armadani; Fathin Muhammad Mardhudhu
DINAMIS Vol. 13 No. 2 (2025): Dinamis : In Press
Publisher : Talenta Publisher

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Abstract

The study utilizes the Single Particle Finite Element Analysis (FEA) method with a Cowper-Symonds Strain Rate Material Model to understand the response of SKD11 tool steel to erosion under varying impact angles and velocities. In this study, SiO₂ particles measuring 0.7 mm in diameter were selected as the erodent, while the target material, SKD11, was sized at 1x1x0,5 mm. The impact angle was varied at 30, 60, and 90 degrees, and the impact velocity was set at 25 and 50 m/s. The simulation results show that SKD11 performs best at lower impact angles. It was observed that as the impact angle increases, the erosion also increases significantly, particularly at 60 degrees. Different impact angles also resulted in different erosion mechanisms on the material's surface. The impact velocity further contributed to an increase in erosion, with material failure and material reduction occurring at 50 m/s.
THE EFFECT OF OFFSET RATIO ON OFFSET JET FLOW STRUCTURE Ramadhani, Rifqi; Julian, James; Wahyuni, Fitri; Purba, Riki Hendra; Madhudhu, Fathin Muhammad; Armadani, Elvi
TURBO [Tulisan Riset Berbasis Online] Vol 14, No 2 (2025): TURBO: Jurnal Program Studi Teknik Mesin
Publisher : Universitas Muhammadiyah Metro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24127/trb.v14i2.4538

Abstract

Jet flow is a crucial fluid dynamic phenomenon that has been extensively studied. It is essential for various industrial applications, including surface cleaning, flow control, and cooling electronic components.  Offset jet is an innovation in jet flow configuration that offers advantages in flow pattern control by expanding the impingement area and regulating surface pressure distribution. This study employed a Computational Fluid Dynamics (CFD) approach to investigate the influence of variations in the offset jet ratio on the aerodynamic characteristics of the flow, specifically the impingement zone area, pressure coefficient distribution, and skin friction coefficient. The standard k-ε turbulence model, utilizing a structured mesh and a Reynolds number of 10,000, was employed in this research. The number of mesh elements used was a fine mesh of 200,000 with an error percentage of 0.09436%. The results of the study show that an offset ratio of 3 produces the highest cf value of 0.0047 and a stable Cp distribution of 0.218, while also providing the best impingement zone area. These findings indicate that OR 3 is the most optimal configuration in terms of aerodynamics for precision system applications, with a focus on flow pattern control and wide impingement zone coverage.