A product lifetime model for assessing the effect of product lifetime extension behavior by different consumer segments

Product lifetime extension would contribute to establishing a circular economy by reducing the environmental impacts of mass consumption. This study developed a product lifetime model that can explicitly deal with the proportion and the longer-use behaviors of different consumer segments. The developed model expressed the product lifetime distribution as the composite of two distribution functions for longer-use promoters and normal-use consumers. The model explicitly deals with two parameters of longer-use actions: increasing the proportion of longer-use promoters and prolonging product lifetimes. A scenario analysis with the developed model showed that if the proportion of longeruse promoters, who uses their products 1.4 times longer than normal consumers, increases to 20%, the domestic demand for new product and the EoL generation will decrease by approximately 5%–10%. The results demonstrated that the model can quantitatively analyze the effects on the domestic demand for new products and the EoL products generation by the tow parameters for longer-use actions. By incorporating this model into a material stock and flow analysis model, it will be possible to assess the effects of promoting longer-use of durable goods on natural resource consumption, greenhouse gas emissions, reduction of final disposal of wastes, etc