Product lifetime

Product lifetime or product lifespan is the time interval from when a product is sold to when it is discarded.^[1]

Product lifetime is slightly different from service life because the latter considers only the effective time the product is used.^[1] It is also different from product economic life which refers to the point where maintaining a product is more expensive than replacing it;^[2] from product technical life which refers to the maximum period during which a product has the physical capacity to function;^[3] and from the functional life which is the time a product should last regardless of external intervention to increase its lifespan.^[4]

Product lifetime represent an important area of enquiry with regards to product design, the circular economy^[5] and sustainable development.^[3] This is because products, with the materials involved in their design, production, distribution, use and disposal (across their life cycle), embody carbon due to the energy involved in these processes.^[6] Therefore, if product lifetimes can be extended, the use of energy, embodied in carbon, can be reduced and progress can be made towards reducing greenhouse gas emissions: Bocken et al.^[7] term this "Slowing resource loops" (309, their emphasis). In addition, excessive waste generation has been attributed to short-lived goods and a throwaway society.^[8]

In recent years, there has been a growth in academic and policy discussions around product lifetimes. For example, discussion of product lifetimes are an integral part of the European Commission's action plan for the circular economy^[9]. In academia, the PLATE (Product Lifetimes and the Environment) Consortium hosts regular conferences and seminars around the topic of product lifetimes and the environment (see: http://www.plateconference.org/). In the business world, the Canadian Kijiji platform's Secondhand Economy Index examines how consumers extend product lifetime through secondhand marketplaces, swapping, donating and renting/leasing/lending/pooling (see: https://www.kijiji.ca/kijijicentral/second-hand-economy/).

This article examines how product lifetimes are defined in the academic literature and discusses how product lifetimes can be measured. A distinction is made between the definition and measurement of actual and expected product lifetimes.