This study focuses on technologies for manufacturing aluminum components and provides a framework for selecting appropriate manufacturing methods from a life cycle economics perspective. Conventional manufacturing and additive manufacturing were examined. Additive manufacturing can manufacture intricate geometries that are difficult to achieve using conventional methods. However, its low productivity and high cost have limited its implementation into the industry. In addition, there is no consensus on the environmental impact of additive manufacturing. To address these issues, we examined the hypothesis that a life cycle cost analysis, which considers environmental impact when selecting a manufacturing method, would enable users to make more reasonable decisions. The study compared the life cycle costs of manufacturing methods for power semiconductors cooling components in electric vehicles and bracket components in aircraft. The results show that greenhouse gas emissions are higher during the use phase than the manufacturing phase for both applications. Replacing conventional manufacturing with additive manufacturing can reduce overall greenhouse gas emissions. Although additive manufacturing has a higher manufacturing cost compared to conventional manufacturing, the life cycle cost analysis reveals an economic advantage in replacing conventional manufacturing with additive manufacturing in aircraft engine brackets when running costs and carbon pricing are taken into consideration.