Various Definitions of Product Lifetimes

Abstract

This article explained various concepts and definitions of product lifetimes. It was shown that various “product lifetime” can be defined according to its starting and ending time points in the product lifecycle; the definitions of product lifetime data that was observed and reported by academic papers and survey reports are diverse; a clear distinction among the definitions is needed. When the product lifetime data is used for a material flow and stock accounting/analysis and lifecycle assessment, the data with an appropriate definition should be selected according to the purpose. This article also introduced that it is possible to estimate the product lifetime with a definition of interest by selecting an estimation approach and original data appropriately.