obsolescence (ob-s<<schwa>>-les-<<schwa>>nts).1. The process or state of falling into disuse or becoming obsolete. 2. A diminution in the value or usefulness of property, esp. as a result of technological advances. • For tax purposes, obsolescence is usu. distinguished from physical deterioration. Cf. DEPRECIATION. [Cases: Taxation 348(4).]

economic obsolescence.Obsolescence that results from external economic factors, such as decreased demand or changed governmental regulations. — Also termed external obsolescence.

Cf. functional obsolescence.

external obsolescence.See economic obsolescence.

functional obsolescence.Obsolescence that results either from inherent deficiencies in the property, such as inadequate equipment or design, or from improvements in the property since its use began. Cf. economic obsolescence.

planned obsolescence.A system or policy of deliberately producing consumer goods that will wear out or become outdated after limited use, thus inducing consumers to buy new items more frequently. — Also termed built-in obsolescence.

[Blacks Law 8th]