Assets that have an indefinite useful life (including goodwill) are not subject to amortization and are tested annually for impairment or whenever events or changes in circumstances indicate that the carrying amount may not be recoverable. Assets that are subject to amortization and investments in affiliates are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount may not be recoverable. An impairment loss is recognized for the amount by which the asset's carrying amount exceeds its recoverable amount. The recoverable amount is the higher of an asset's fair value less cost to sell and the value in use.
To carry out these tests, assets are grouped at the lowest levels for which there are separately identifiable cash flows (each, a CGU). When evaluating long-lived assets for potential impairment, the Company estimates the recoverable amount based on the value in use of the corresponding CGU. The value in use of each CGU is determined on the basis of the present value of net future cash flows which will be generated by the assets tested.
Determining the present value of future cash flows involves highly sensitive estimates and assumptions specific to the nature of each CGU's activities, including estimates and assumptions relating to amount and timing of projected future cash flows, expected changes in market prices, expected changes in the demand of Ternium products and services, selected discount rate and selected tax rate.
Ternium uses cash flow projections for the next five years based on past performance and expectations of market development; thereafter, it uses a perpetuity rate. Application of the discounted cash flow (DCF) method to determine the value in use of a CGU begins with a forecast of all expected future net cash flows. Variables considered in forecasts include the gross domestic product (GDP) growth rates of the country under study and their correlation with steel demand, level of steel prices and estimated raw material costs as observed in industry reports.
Cash flows are discounted at rates that reflect specific country and currency risks associated with the cash flow projections. The discount rates used are based on the weighted average cost of capital (WACC), which is considered to be a good indicator of cost of capital. As of December 31, 2017 the discount rate used to test goodwill allocated to the Steel and Mining Mexico CGUs for impairment was 11.49% (as of December 31, 2016, 10.82%).
As a result of the above factors, actual cash flows and values could vary significantly from the forecasted future cash flows and related values derived using discounting techniques. Based on the information currently available, however, Ternium believes that it is not reasonably possible that the variation would cause the carrying amount to exceed the recoverable amount of the CGUs.
Except for the impairment in connection with the investment in Usiminas in 2015 and 2014, during the years 2017, 2016 and 2015, no impairment provisions were recorded in connection with assets that have an indefinite useful life (including goodwill).
