BUENAVENTURA MINING CO INC | CIK:0001013131 |

 

The preparation of the Group’s consolidated financial statements requires Management to make judgments, estimates and assumptions that affect the reported amounts of revenues, expenses, assets and liabilities, and the accompanying disclosures, and the disclosure of contingent liabilities. The estimates and assumptions are continuously evaluated and based on Management´s experience and other facts, including the expectations about future events which are reasonable under current situation. Uncertainty about these estimates and assumptions could result in outcomes that require material adjustment to the carrying amount of assets and liabilities affected in future periods. Further information on each of these areas and how they impact the various accounting policies are described below and also in the relevant notes to the consolidated financial statements.

 

In the process of applying the Group’s accounting policies, Management has made the following judgments, which have the most significant effect on the amounts recognized in the consolidated financial statements:

 

By their nature, contingencies will be resolved only when one or more uncertain future events occur or fail to occur. The assessment of the existence and potential quantum of contingencies inherently involves the exercise of significant judgment and the use of estimates regarding the outcome of future events.

 

The Group assesses the status of each exploration project of its mining units to determine when the development phase begins. One of the criteria used to evaluate the development start date is when the Group determines that the property can be economically developed.

 

The Group assesses the stage of each mine under development to determine when a mine moves into the production phase. The criteria used to assess the start date are determined based on the unique nature of each mining project, such as the complexity of the project and its location. The Group considers various relevant criteria to assess when the production phase is considered to have commenced. Some of the criteria used to identify the production start date include, but are not limited to:

 

 

When a mine development /construction project moves into the production phase, the capitalization of certain mine development costs ceases and costs are either regarded as forming part of the cost of inventory or expensed, except for costs that qualify for capitalization relating to mining asset additions or improvements. It is also at this point that depreciation or amortization commences.

 

The key assumptions concerning the future and other key sources of estimation uncertainty at the reporting date that have a significant risk of causing a material adjustment to the carrying amounts of assets and liabilities within the next financial year, are described below. The Group based its assumptions and estimates on parameters available when the consolidated financial statements were prepared. Existing circumstances and assumptions about future developments, however, may change due to market change or circumstances arising beyond the control of the Group. Such changes are reflected in the assumptions when they occur.

 

The Group calculates its reserves using methods generally applied by mining and industry according to international guidelines. All estimated reserves represent estimated quantities of mineral proven and probable that under current conditions can be economically and legally processed.

 

The process of estimating quantities of reserves is complex and requires making subjective decisions when evaluating all geological, geophysical, engineering and economic information available choices. Reviews could occur on reserve estimates due to, among others, revisions to the data or geological assumptions, changes in prices, production costs and results of exploration activities. Changes in estimated reserves could mainly affect the carrying value of mining concessions, development costs and property, plant and equipment; the charges in result for depreciation and amortization; and the carrying amount of the provision for closure of mining units.

 

Estimated economically recoverable reserves are used in determining the depreciation and/or amortization of mine-specific assets.

 

This results in a depreciation/amortization charge proportional to the depletion of the anticipated remaining life-of-mine production. The life of each item, which is assessed at least annually, has regard to both its physical life limitations and present assessments of economically recoverable reserves of the mine property at which the asset is located. These calculations require the use of estimates and assumptions, including the amount of recoverable reserves. Changes in estimates are accounted for prospectively.

 

The Group assesses its mine rehabilitation provision at each reporting date using a desconted future cash flow method. In determining the amount of the provision, it is necessary to make significant assumtions and estimates, becasuse exist many factors that can affect the final amount of this provision. This factors includes estimates of the extent and costs of rehabilitation activities, technological changes, regulatory changes, cost increases as compared to the inflation rates, and changes in discount rates and periods in which is expected that such costs will be incurred. These uncertainties may result in future actual expenditure differing from the amounts currently provided. The provision at reporting date represents Management’s best estimate of the present value of the future rehabilitation costs required.

 

Inventories are classified in short and long term in accordance with the time that Management estimates will start the production of the concentrate extracted from the mining unit.

 

Net realizable value tests are performed at each reporting date and represent the estimated future sales price of the product the entity expects to realize when the product is processed and sold, less estimated costs to complete production and bring the product to sale.

 

The Group assesses each asset or cash generating unit in each reporting period to determine whether any indication of impairment exists. Where an indicator of impairment exists, a formal estimate of the recoverable amount is made, which is considered to be the higher of the fair value less costs of disposal and value in use. The assessments require the use of estimates and assumptions such as long-term commodity prices, discount rates, operating costs, among others. These estimates and assumptions are subject to risk and uncertainty.

 

The fair value of mining assets is generally calculated by the present value of future cash flows arising from the continued use of the asset, which include some estimates, such as the cost of future expansion plans, using assumptions that a third party might consider. The future cash flows are discounted to their present value using a discount rate that reflects current market assessment of the value of money over time, as well as specific risks of the asset or cash-generating unit under evaluation. The Group has determined the operations of each mining unit as a single cash generating unit.

 

Deferred tax assets are recognized for unused tax losses to the extent that it is probable that taxable profit will be available against which the losses can be utilized. Significant Management judgment is required to determine the amount of deferred tax assets that can be recognized, based upon the likely timing and the level of future taxable profits together with future tax planning strategies. 

 

The contingent consideration arising from a business combination is measured at fair value at the date of acquisition, as part of the business combination. If the contingent consideration is eligible to be recognized as a financial liability the fair value is subsequently re-measured at each date of the consolidated financial statements. Determining the fair value of the contingent consideration is based on a model of discounted future cash flows. The key assumptions take into account the likelihood of achieving each goal of financial performance as well as the discount factor.