ANALISIS PENGENDALIAN PERSEDIAAN PYLON PIN RIB DENGAN METODE FORECASTING DAN LOT SIZING PADA PESAWAT AIRBUS 330 DI PT GMF AEROASIA TBK.

Manajemen inventaris komponen aviasi merupakan pilar fundamental dalam efisiensi operasional industri Maintenance, Repair, and Overhaul (MRO). Studi ini menginvestigasi inefisiensi dalam pengendalian persediaan komponen kritis Pylon Pin Rib (P/N F5453255320000) di PT. GMF Aeroasia Tbk. untuk pesawat Airbus 330. Analisis data operasional selama 24 bulan (2023-2024) mengidentifikasi 12 insiden kekosongan stok (out of stock) yang secara langsung berimplikasi pada keterlambatan Turn Around Time (TAT), metrik kinerja utama yang dapat menimbulkan konsekuensi finansial berupa denda hingga USD 2,500 per hari. Untuk mengatasi masalah ini, penelitian menerapkan pendekatan kuantitatif guna memvalidasi metode forecasting dengan akurasi prediktif tertinggi. Dari dua belas model Time Series yang dievaluasi menggunakan metrik MAD, MSE, dan MAPE, metode Trend Projection - Least Square terbukti paling unggul dengan nilai kesalahan terendah (MAD=9,292; MSE=152,449; MAPE=53,754). Berdasarkan hasil forecasting yang telah divalidasi, lima metode lot sizing kemudian disimulasikan untuk menentukan strategi pengadaan paling efisien secara ekonomis. Hasil analisis komparatif menunjukkan bahwa metode Fixed Period Requirement (FPR) dengan siklus pemesanan tiap empat bulan merupakan strategi paling optimal, yang mampu menekan total biaya persediaan terendah hingga Rp 11.644.082.042. Sebagai mitigasi risiko terhadap volatilitas permintaan, direkomendasikan pula implementasi safety stock sebanyak 16 unit, yang dihitung berdasarkan target service level 90%. Dengan demikian, integrasi antara forecasting yang akurat dan strategi lot sizing yang efisien ini memberikan solusi aplikatif bagi perusahaan untuk meningkatkan ketersediaan komponen, mengurangi keterlambatan TAT, dan memperkuat efisiensi operasionalnya.

Kata Kunci: Forecasting, Lot Sizing, Pengendalian Persediaan, Pylon Pin Rib, Turn Around Time

Aviation component inventory management is a fundamental pillar of operational efficiency in the Maintenance, Repair, and Overhaul (MRO) industry. This study investigates the inefficiencies in the inventory control of the critical Pylon Pin Rib component (P/N F5453255320000) at PT. GMF Aeroasia Tbk. for the Airbus 330 aircraft. An analysis of 24 months of operational data (2023–2024) identified 12 stock-out incidents that directly implicated delays in Turn Around Time (TAT), a key performance metric that can lead to financial consequences in the form of penalties up to USD 2,500 per day. To address this problem, the research applies a quantitative approach to validate the forecasting method with the highest predictive accuracy. From twelve time-series models evaluated using MAD, MSE, and MAPE metrics, the Trend Projection - Least Square method proved to be superior, with the lowest error values (MAD=9.292; MSE=152.449; MAPE=53.754). Based on the validated forecasting results, five lot-sizing methods were then simulated to determine the most economically efficient procurement strategy. The comparative analysis shows that the Fixed Period Requirement (FPR) method, with a four-month ordering cycle, is the most optimal strategy, capable of reducing the total inventory cost to a minimum of IDR 11,644,082,042. As a risk mitigation measure against demand volatility, the implementation of a safety stock of 16 units is also recommended, calculated based on a 90% target service level. Thus, the integration of accurate forecasting and an efficient lot-sizing strategy provides an applicable solution for the company to increase component availability, reduce TAT delays, and strengthen its operational efficiency.
Keywords: Forecasting, Inventory Control, Lot Sizing, Pylon Pin Rib, Turn Around Time