A framework for stepwise life cycle assessment during product design with case-based reasoning

Life cycle assessment (LCA) is a systematic method of analyzing the environmental load throughout the entire life cycle of a product and evaluating potential environmental effects. It can be useful for ecodesign and for dealing with environmental regulations. However, the LCA process generally requires considerable time and money to collect relevant data and information. Although various studies have been made on the streamlined LCA in an effort to overcome these limitations, the result is still unsuitable for active ecodesign in the early design stage. We therefore propose an approximate LCA method for the early stage of product design and a systematic selective LCA method for use after the detail design stage. For the approximate LCA, we used the function behavior structure environmental effect expression to develop an environmental character evaluation matrix and a case-based reasoning system. This case-base reasoning system can be used in each design stage by referring to the LCA results of a product or a part or module. In addition, the concept of relative importance is used to select the important parts or modules considered in the selective LCA. A case study involving a mobile phone confirms that the proposed stepwise LCA method can be effectively applied to the design of eco-products.