DiE: Jurnal Ilmu Ekonomi dan Manajemen

Inventory Control of Steel Materials in Shipyard Company Using the Continuous Review Method

ida bagus riscy adhastyananda — 2026-02-24

Ship repair activities are characterized by highly uncertain material requirements because the scope of work is often finalized only after on-dock inspection. This uncertainty frequently leads to material shortages, project delays, and increased operational costs, particularly in replating processes where steel is the primary material. This study aims to develop an improved inventory control policy by integrating demand forecasting and continuous review inventory modeling. An ABC classification was first conducted to identify high-value materials requiring strict control, with Category A items selected for further analysis. Demand forecasting was performed using Exponential Smoothing and Long Short-Term Memory (LSTM) models, and forecasting accuracy was evaluated using Mean Absolute Deviation (MAD) and Mean Squared Error (MSE). The method with the lowest error was then incorporated into a Continuous Review (Q) Model with Backorders to determine optimal order quantities, safety stock, and reorder points. A simulation comparing the proposed policy with the company’s existing practice shows that the proposed approach reduces total inventory-related costs by IDR 2,671,910,250.20, equivalent to a 7.645% cost saving, while improving material availability and reducing shortage risks. The findings demonstrate that combining machine-learning-based forecasting with probabilistic inventory control can significantly enhance inventory performance in project-based industries with fluctuating demand, such as ship repair.

DETERMINANTS OF GDP PER CAPITA IN BRICS AND ASEAN COUNTRIES: A QUANTILE REGRESSION APPROACH

Ratika Auderi — 2026-02-24

This study investigates the determinants of GDP per capita in BRICS and ASEAN countries by accounting for heterogeneity across income levels. While previous research predominantly relies on mean-based estimation methods, such approaches may conceal variations in how growth factors operate across different stages of development. Using panel data from 21 countries over the period 2010–2023, this study applies quantile regression to examine how macroeconomic factors, labor productivity, and institutional quality influence GDP per capita at the 0.25, 0.50, and 0.75 quantiles.

The results reveal that household consumption significantly promotes GDP per capita only in middle- and upper-income countries, while foreign direct investment and government expenditure show no significant effects across quantiles. In contrast, labor productivity and political stability consistently exert strong positive influences at all income levels, indicating their fundamental role in sustaining economic growth. Government effectiveness becomes significant only in higher-income countries, suggesting that institutional capacity yields greater returns as economies mature.

These findings highlight that productivity enhancement and institutional stability, rather than capital inflows alone, are the primary drivers of income growth in emerging economies. The study underscores the importance of policies focused on human capital development, structural transformation, and governance improvement to achieve inclusive and sustainable economic growth.