A fuzzy logic-based approach to determine product component end-of-life option from the views of sustainability and designer's perception

In our time, an increasing awareness of short and long-term environmental impacts is driving manufacturers to reconsider the product design process with a view toward sustainability. Manufacturers have begun to consider the need for responsible resource use and management during the product life cycle, particularly during the product retirement phase. The determination of appropriate end-of-life (EOL) options for retired product components is a crucial issue relative to most manufactured products. To address it, the product design process must be modified to consider sustainability in a comprehensive manner. At present, only limited existing research integrates social sustainability into EOL option determinations; that gap, in part, stimulates this study. We also recognize that a product designer's background and experience will directly affect the EOL strategy selection. Therefore, incorporating the designer's perception along with sustainability dimensions into an EOL strategy determination is essential and also motivates this investigation. In our proposed approach, quantitative indicators are used to assess sustainability dimensions - economic (residual value), environmental (Eco-indicator) and social impact (job creation, human toxic potential and land use) - for each EOL option. The primary merit of this approach is transferring the essential but not directly relevant design preferences into sustainability analysis through fuzzy logic-based transformation equations. An expected value is derived to represent the sustainability value of each EOL option. An automobile gasoline engine is used as a case study to illustrate the methodology.