Service life

This article is about the manufacturing concept. For the economic concept of service life, see Fixed capital.

British Rail Class 483 trains, first built in 1938, were 83 years old when they were withdrawn from the Isle of Wight in January 2021; they were the oldest trains in Great Britain remaining in regular passenger service at the time.[1][2] That honour was passed to the currently 52 year old London Underground 1972 Stock trains still in service on the Bakerloo line.

A product's service life is its period of use in service. Several related terms describe more precisely a product's life, from the point of manufacture, storage, and distribution, and eventual use. Service life has been defined as "a product's total life in use from the point of sale to the point of discard" and distinguished from replacement life, "the period after which the initial purchaser returns to the shop for a replacement".[3] Determining a product's expected service life as part of business policy (product life cycle management) involves using tools and calculations from maintainability and reliability analysis. Service life represents a commitment made by the item's manufacturer and is usually specified as a median. It is the time that any manufactured item can be expected to be "serviceable" or supported by its manufacturer.[citation needed]

Service life is not to be confused with shelf life, which deals with storage time, or with technical life, which is the maximum period during which it can physically function.[3] Service life also differs from predicted life, in terms of mean time before failure (MTBF) or maintenance-free operating period (MFOP). Predicted life is useful such that a manufacturer may estimate, by hypothetical modeling and calculation, a general rule for which it will honor warranty claims, or planning for mission fulfillment. The difference between service life and predicted life is most clear when considering mission time and reliability in comparison to MTBF and service life. For example, a missile system can have a mission time of less than one minute, service life of 20 years, active MTBF of 20 minutes, dormant MTBF of 50 years, and reliability of 99.9999%.

Consumers will have different expectations about service life and longevity[4][5] based upon factors such as use, cost, and quality.

  1. ^ Clifton, Paul (4 January 2021). "Island Line bids farewell to "icon of transport"". Rail. Bauer Consumer Media. Archived from the original on 8 January 2021. Retrieved 8 January 2021.
  2. ^ Clinnick, Richard (4 January 2021). "Island Line bids farewell to "icon of transport"". RAIL. Archived from the original on 8 January 2021. Retrieved 8 January 2021.
  3. ^ a b Cooper, Tim (1994). Beyond Recycling: the longer life option. London: New Economics Foundation. p. 5. ISBN 9781889407005.
  4. ^ Evans, Sian; Cooper, Tim (2010). "Consumer Influences on Product Life-Spans". In Cooper, Tim (ed.). Longer Lasting Products. Farnham: Gower. pp. 319–350. ISBN 9780566088087.
  5. ^ "Drive it forever" Club Lexus Forums