Ameha MulugetaEphrem Zemedkun2026-04-042026-04-042025-10-01https://etd.aau.edu.et/handle/123456789/8050The manufacturing industry is increasingly pressured to improve efficiency, reduce waste, and meet rising customer demand in competitive markets. In Ethiopia, the Ethiopian Construction Works Corporation - Geosynthetics Industrial Works (ECWC GIW) faces persistent production inefficiencies that limit throughput and competitiveness. This study aims to enhance production process efficiency through the integration of Value Stream Mapping (VSM) and Discrete Event Simulation (DES). VSM was applied to map the current production system, distinguish between value adding (VA) and non-value-adding (NVA) time and activities, and identify bottlenecks. DES was then employed to dynamically model the production process, validate VSM findings, and test improvement scenarios. The results revealed that the Barrel Vacuum process is the dominant bottleneck, accounting for the largest share of accumulated VA time and constraining system throughput. Additional inefficiencies were identified in the Raw Material Input, Holing, and Cutting processes, which are manual in nature and contribute to delays and waste. Improvement scenarios, including automation of Raw Material Input, workflow layout redesign, and optimization of Holing, Cutting, and Belling Socket, were evaluated using DES. The findings indicated that automation of Raw Material Input alone reduced its mean processing time by nearly 60%, while system-wide improvements increased throughput from 9 tons to 11 tons per day. This represents a 22.22% increase in production capacity, moving the company closer to its production target of 12 tons per day. The study contributes both theoretical and practical insights. Academically, it demonstrates the complementary strengths of VSM and DES, highlighting their value when integrated for process analysis and improvement. Practically, it provides ECWC GIW with a structured roadmap for reducing waste, eliminating bottlenecks, and sustaining continuous improvement. More broadly, the findings underscore the applicability of lean-simulation integration as an effective methodology for enhancing production efficiency in developing economy manufacturing contexts.en-USValue Stream Mapping (VSM)Discrete Event Simulation (DES)Lean ManufacturingProduction EfficiencyEthiopian Manufacturing IndustryThesis