Planned obsolescence is the concept that a product should be designed and produced with the knowledge that it will only be popular, useful and functional for a limited length of time.
The term planned obsolescence was popularized in the 1950s by industrial designer Brooks Stevens, who proposed that corporations should think about a product's entire lifecycle during the design phase and anticipate the consumer's natural desire to continually own something a little newer and a little better. Stevens proposed that an iterative approach to product design would not only help keep production costs down, it would also inspire the consumer to make a purchase a little sooner than might be absolutely necessary, which in turn, would keep the economy growing and create a secondary market for used products.
Over the years, critics have blamed the concept of planned obsolescence for everything from poor product quality to the creation of a disposable society that no longer knows what it's like to live in a world where products were "built to last." Proponents of planned obsolescence point out that technology is changing very quickly and it is simply common sense for manufacturers to acknowledge the end of a product's lifecycle and plan ahead for it.
In the computer industry, where iterative software and hardware releases cause obsolescence to occur much faster than in other industry sectors, failure to plan for obsolescence is a real concern. In many data centers, where refresh cycles occur every three years and e-waste disposal is legislated, hardware must be discarded in an environmentally responsible way.