Most products have the potential to negatively impact the environment during all life-cycle stages. However, most environmental impact assessment methods focus on a single product life-cycle and on a specific lifecycle stage. In addition, consumer products can potentially amplify these impacts with their larger production volumes, wide dispersion, and miniaturization trends. The main objective of this project is to develop and validate a design optimization framework that allows for understanding the environmental impact of design decisions (e.g. materials substitution, etc.) across all life-cycle stages in consumer products. The methodology relies on multi-attribute utility theory and non-linear mathematical programming. A preliminary framework is proposed.