Manufacturing system productivity of Yetmen Gypsum and Gypsum Products Manufacturing & Sales Plc is low. Average plant capacity utilization rate of the firm within last four consecutive years is 44.43%. This research aims to enhance manufacturing system productivity of YGMS Plc using system dynamics by the application of Vensim Software to identify inefficiencies, simulate potential improvements, and implement data driven strategies for continuous operational enhancements. Findings of this study showed that major factors significantly affecting manufacturing system productivity of YGMS Plc are resource related downtime, human error, maintenance related downtime, and management related issue. Experimentation of simulation model considering time dynamics of modeled manufacturing system indicated that policy intervention based on the findings of this research improved the company’s productivity from 0.119616Kg/Birr to 0.371381Kg/Birr. Also model validation test defined the real problem of the manufacturing system. When plant downtime hours due to human error related factors, resource related factors, and maintenance related factors of the SD model are separately decreased by 20%, the multifactor productivity of the firm are increased by 5.84%, 12.98% and 2.69% respectively. Hence, the scenario analysis indicated that all factors have significant effect in the multifactor productivity of the firm. However, resource related factors have the highest effect in the improvement of multifactor productivity of YGMS Plc followed by human error related factors and maintenance related factors respectively. Therefore, policy intervention of YGMS Plc for its productivity enhancement shall focus to improve resource related factors, human error, and maintenance related factors affecting the firm’s productivity. Key Words: Productivity improvement, System dynamics, Quantitative model, Conceptual Model, Factor analysis, Sensitivity analysis.