This document discusses product life cycle design and environmental requirements. It introduces life cycle assessment (LCA) as a quantitative method to evaluate the environmental impacts of a product over its entire life cycle, from material extraction and production to distribution, use, and disposal. The document outlines how LCA examines a product's life cycle stages and functional unit to associate its environmental effects, such as global warming, ozone depletion, eutrophication, and waste generation. Examples of applying LCA to upholstered seats and refrigerators are also provided.