Service lifetimes of mineral end uses

摘要: Reliable information for the lifetime distribution (LTD) of products is essential for determining current and future waste flows, for designing end-of-life management strategies, and therefore for improving resource efficiency of materials and energy. There is, however, a lack of both, methodology to determine the probability density functions for life expectancies of products, and solid quantitative data based on case studies. In this report, we describe five approaches to determine the LTD of products using a combination of material flow modeling and survival analysis. Two of these approaches are applied to the following product categories: dwellings, passenger cars, refrigerators, air conditioners, CRT TV sets, and CRT computer monitors. The analysis was performed using data from various literature sources and a field study conducted during the summer of 2007. While the lifetime distribution of appliances is best approached with Weibull functions, passenger cars tend to follow normal distributions, and dwellings lognormal distributions. The lifetime expectancy of passenger cars has continuously increased since the 1960s, but experienced a pronounced increase for vehicles manufactured between 1985 and 1990. One important factor for this sudden increase in lifetime expectancy might be the introduction of zinc-coated steel for corrosion protection.