Assets should be analysed into major components with
substantially different useful economic lives, but there
is no requirement to separately depreciate parts of an
asset.
In some industries (e.g., water industries) renewals
accounting is applied in accounting for tangible fixed
assets within a system or network.
Depreciation ceases at the end of the useful life or on
disposal of the asset.
If no depreciation is charged (as immaterial) or the
remaining useful life of asset exceeds 50 years, a
mandatory annual impairment review is required.