Service life in the context of Design life

Durability is the ability of a physical product to remain functional, without requiring excessive maintenance or repair, when faced with the challenges of normal operation over its design lifetime. There are several measures of durability in use, including years of life, hours of use, and number of operational cycles. In economics, goods with a long usable life are referred to as durable goods.

Because there is no objective measure of durability for clothing, price has become an important indicator.

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

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

Vehicle recycling or automobile scrapping is the dismantling of vehicles for spare parts. At the end of their useful life, vehicles have value as a source of spare parts and this has created a vehicle dismantling industry. The industry has various names for its business outlets including wrecking yard, auto dismantling yard, car spare parts supplier, and recently, auto or vehicle recycling. Vehicle recycling has always occurred to some degree but in recent years manufacturers have become involved in the process. A car crusher is often used to reduce the size of scrapped vehicles for simplified transportation to a steel mill.

Approximately 12-15 million vehicles reach the end of their useful life each year in just the United States alone. These automobiles, although no longer roadworthy, can still have a purpose by giving back the metal and other recyclable materials that are contained in them. The vehicles are shredded and the metal content is recovered for recycling, while in many areas, the rest is further sorted by machine for recycling of additional materials such as glass and plastics. The remainder, known as automotive shredder residue, is put into a landfill.