Design for Environment aims to yield a product whose aggregate environmental impact is as small as possible. This thesis characterizes a product recovery system and defines the concepts of product lifetime and part lifetime. A multi-lifecycle product recovery model is developed based on the concepts of product tree and disassembly path representation, four product recovery choices, time varying costs, cost comparison. The four product recovery choices of a part in the product tree are: Reconditioning, Part Remanufacturing, Material Recycling, and Landfill. This thesis focuses on how to improve the product design while minimizing environmental impact of the product and introduces an indirect product design improvement method based on the concept of candidate set. A monitor and a Personal Computer are used to illustrate the model and method. A PC Windows 95 software based computer aided DFE tool is partially implemented to demonstrate our method and model. More research and development is needed to implement a complete DFE tool incorporating Multi-lifecycle Engineering concept. The obtained model and results will play an important role in research and development of Multi-lifecycle engineering product design and guide designers in their product and process design.