6.3. Depreciation and Amortization
Fixed assets (excluding land) are depreciated / amortized using straight-line method over the useful life of the asset. Following are the useful economic lives of various assets:
| Assets | Useful Economic Life (years) |
| Buildings and construction | 40 |
| Machinery and equipment | 10 |
| Computers, computer parts, software | 3 |
| Intangible assets with indefinite useful life | 10 |
| Intangible assets with definite useful life (includes license for mineral exploration and extraction) (refer note 1) | Validity period |
| Other non-current assets | 10 |
| Manufacturing building and facilities and buildings within technology park | 20 |
| Machineries, equipment, technical parts of machinery used in the technology park, unit of production | 3 |
Note 1: The cost base for calculating depreciation on a mineral exploration and extraction license is the sum of its purchase price and fees paid for the ownership and transference of such license.