Sustainable Life Cycle Design Using Constraint Satisfaction Problems and Quality Function Deployment
Résumé
In many ecodesign problems, finding solutions that complete the design requirements while bettering multiple performances (environmental impacts, costs, etc.) is no trivial task. Design-aid tools using optimization methods are efficient to address these issues but fail to encompass the whole life cycle of products and customer attractiveness aspects. This article describes an original method using CSP optimization and QFD to generate an optimized model of a product during the early design stages. Scores from the QFD matrix are used to weight the sub objectives of the optimization so that the solving is strongly dependent on the customers’ demands. As a consequence, the method allows a better integration of customer needs during the design process. To optimize multiple performances, the variables of the model are used to create impact functions corresponding to environmental impacts, costs, etc. of every life cycle phases of the product's parts. As a result, the optimized model is the one with the best performance scores while answering best the variety of customers’ needs. The methodology is applied to the design of an innovative inflatable dinghy. Results show that the use of QFD generates a fewer improvement of the environmental performance compared to an environmentally focused optimization (10% vs 18%) but it guarantees that the product will better meet customers’ needs. Hence, the product should more likely be accepted and purchased and have a positive impact on the performances of the whole market.