Obsolescence takes place when something is no longer maintained or required, even if it could still be usable. Planned obsolescence takes place when obsolescence is actively designed and initiated by the manufacturer/maintainer.

The concept of obsolescence is generally add odds with technological diversity and often also wasteful especially in the case of planned obsolescence.

Types of planned obsolescence

• Obsolescence of desirability: When designers change the styling of products so customers will purchase products more frequently due to the decrease in the perceived desirability of unfashionable items.
• Obsolescence of function: When an item is produced to break down or otherwise become non-functional in an abnormally short period of time.
• Obsolescence of compatibility: When a product becomes obsolete by altering the system in which it is used in such a way as to make its continued use difficult. Common examples of planned systemic obsolescence include not accommodating forward compatibility in software.
• Pseudo-obsolescence of desirability: When planned obsolescence appears to introduce innovative changes into a product, but in reality does not, often forcibly outfashioning an otherwise-useful product.

Examples

• Non-user-replaceable batteries: Some products, such as mobile phones, laptops, and electric toothbrushes, contain batteries that are not replaceable by the end-user after they have worn down, therefore leaving an aging battery trapped inside the device.
• Phoebus cartel: The cartel conveniently lowered operational costs and worked to standardize the life expectancy of light bulbs at 1,000 hours, down from 2,500 hours, and raised prices without fear of competition.