Longevity and Sustainability

From energypedia


Being responsible custodians of our environment requires that we treasure our natural resources, and make the best possible use of them.

The ideal would be that all the raw materials that go into a product are re-used, and the only net resource consumed during the product’s lifetime is energy.  However, this is almost never achieved.

If we cannot achieve this, the next best thing we can do is ensure that whatever we produce has a long and productive life, so that as much utility as possible is gained for each kilogram of waste eventually produced.  This is not simply a matter of Quality Assurance during manufacture - there are at least four distinct aspects to ensuring longevity and sustainability for a solution based on technology:

  • Build Quality / Durability
  • Repairability
  • Independence
  • Recyclability

Only two of these relate to actions before the product is supplied, one imposes obligations on the manufucturer for the entire life of the product, and one relates to what happens at the end of life.  However, all must be considered, in order to assess sustainability.

Build Quality / Durability

Assessing Build Quality (or Durability) is the process of determining the product’s ability to survive misuse and environmental stresses, including time.  This can be done just before the first release of the product – but when there is still time to make changes as a result of testing.  It needs to be repeated after every significant design change.

A product that could survive any environment stress or misuse would be impossibly expensive to build, and unwieldy to use – so it is inevitable that some equipment will fail in the field. 


An assessment of Repairability determines the probability that someone with fewer facilities than the manufacturer will at some future date be able to remediate the harmful effects of environment or misuse.  Repairability can also be assessed before product release.  (A Draft Repairability Specification has been uploaded to this wiki.)

However, hardware failure is not the only thing that can end a product’s useful life. Unlike traditional items we purchase, hi-tech products today remain dependent on the manufacturer throughout their life – for:

  • Supplies of spare parts that cannot be simply copied or obtained elsewhere,
  • Software maintenance – to:

            - Fix bugs

            - Head off new virus threats

            - Cope with changes in the situation the equipment has to deal with

            - Provide continued compatibility with other equipment containing software that has been upgraded,

  • Some products only function by talking to a server maintained by the manufacturer
  • Although the hardware is purchased, the software may be only licensed, and that licence may not be renewed.

If the manufacturer stops providing these functions for any reason at all, the product may suddenly become useless.  We don’t have a good word for this continued dependence on the manufacturer after purchase, but it is often the dominant factor in determining end-of-life.   Outright ownership of a product used to mean that once bought and paid for, no-one could stop you using it, but in the hi-tech world this is actually no longer true.


The degree of dependence or independence cannot be assessed prior to product release, as it is a function of how the manufacturer behaves after the sale.  A wise purchaser would build an obligation on the manufacturer to provide these services for a period of time into the purchasing contract.The period of time should be the expected useful life of the product, i.e. longer than the warranty period.


When, finally, the end of the product’s life is unavoidable, it may be possible to re-purpose part of the product, and depending on the design, it may be easy or difficult to separate out and extract the most valuable resources (for example precious metals).  This Recyclability can also be assessed prior to product release, but this is as yet rarely done.

Further Information

  • A Review of Small Off-Grid Electricity Systems


  • Contact the author for any questions or comments about the article