This empirical study investigates the relationship between the inventory trends of M113 armored vehicles and sustainable design strategies in the defense sectors of Türkiye and the USA with the perspective of industrial design. Utilizing ARIMA modeling and linear correlation analysis, data collected up to 2022 reveals distinct patterns in vehicle inventory dynamics. The ARIMA analysis produced reliable coefficients despite limited data availability, suggesting feasible numerical assessments. Results indicate that in the USA, the introduction of alternative vehicles such as the Bradley, designed with sustainable principles, led to the phased reduction of M113s. Conversely, Türkiye's inventory trends reflect a linear relationship between the absence of vehicles with design integrity and sustained M113 usage, with modernization efforts prolonging its presence. The study underscores the economic advantages of implementing sustainable product design strategies in armored vehicle development, particularly evident in the USA's production of the Abrams tank and Bradley tracked armored carrier. Despite Türkiye's prolonged reliance on M113s, it highlights the necessity of comprehensive feedback mechanisms and professional units to perform sustainable design strategies. Moreover, it reveals the inefficiency of solely relying on modernization for operational vehicle counts in developing countries, emphasizing the importance of balancing technological advancements with vehicle design integrity. This study sheds light on the evolving nature of sustainable design strategies in defense sectors, urging countries to integrate comprehensive feedback mechanisms and design integrity principles into their armored vehicle development processes for long-term effectiveness and economic viability.