The concept of carbon footprint controllable product is proposed to assess carbon footprint during the stage of
product development and configuration. It’s different from carbon footprint assessment afterwards. As a result, the control
objectives can be quantified accurately and realized easily. Relations among product characteristics, which include carbon
footprint, are uncertain. In order to obtain the optimal product configuration scheme based on constraint of carbon footprint,
three-stage theory is proposed. These three stages refer to functional configuration, compliance evaluation of carbon
footprint, and optimal comprehensive evaluation. Using this theory, functional feasible solution set, carbon footprint conforming
set and the optimal scheme are generated respectively. Grey relation analysis is verified as an effective method
for comprehensive benefit evaluation. Reducer design is used as a case study to illustrate the proposed concept.