The practical answer IAS 16 is not mainly a rule about calculating depreciation. It is a decision process that starts when money is spent and continues until the asset leaves the books. The accountant must decide whether the expenditure creates or improves a resource that will be used for more than one period, which costs belong in the asset, when the asset is ready for use, how its significant parts are consumed, and when an impairment or disposal entry is required. The everyday discipline is simple: identify the asset, build a supported cost, record the available-for-use date, separate significant components, choose a consumption pattern, review estimates and reconcile the fixed-asset register to the general ledger. A mathematically correct depreciation charge can still be wrong if any earlier decision was wrong. What IAS 16 covers IAS 16 applies to tangible items held for production, supply, rental or administration that are expected to be used for more than one period. Co...