Westgold Resources Limited Annual Report 2021

64 Westgold Resources Limited Annual Report 2021 for the year ended 30 June 2021 FINANCIAL REPORT NOTES TO THE CONSOLIDATED FINANCIAL STATEMENTS 3. S IGNIFICANT ACCOUNTING JUDGEMENTS, ESTIMATES AND ASSUMPTIONS (CONTINUED) Significant accounting estimates and assumptions (continued) These calculations require the use of estimates and assumptions, including the amount of recoverable reserves and estimates of future capital expenditure. The calculation of the UOP rate of depreciation could be impacted to the extent that actual production in the future is different from current forecast production based on economically recoverable reserves, or if future capital expenditure estimates change. Changes to economically recoverable reserves could arise due to changes in the factors or assumptions used in estimating reserves, including: – The effect on economically recoverable reserves for differences between actual commodity prices and commodity price assumptions – Unforeseen operational issues. Impairment of capitalised mine development expenditure, property, plant and equipment The future recoverability of capitalised mine development expenditure, property, plant and equipment is dependent on a number of factors, including the level of proved and probable reserves, and the likelihood of progressive upgrade of mineral resources in to reserves over time. In addition, consideration is given to future technological changes, which could impact the cost, future legal changes (including changes to environmental restoration obligations), and changes in commodity prices. Non-financial assets are reviewed for impairment if there is any indication that the carrying amount may not be recoverable. When applicable, FVLCD is estimated based on discounted cash flows using market based commodity prices and foreign exchange rate assumptions, estimated quantities of recoverable minerals, production levels, operating costs and capital requirements, based on the relevant CGU’s life-of-mine (LOM) plans. Consideration is also given to analysts’ valuations. The fair value methodology adopted is categorised as Level 3 in the fair value hierarchy. In determining the VIU, future cash flows for each CGU (i.e. each mine site) are prepared utilising management’s latest estimates of: – the quantities of ore reserves and mineral resources for which there is a high degree of confidence of economic extraction; – royalties and taxation; – future production levels; – future commodity prices; – future cash costs of production and development expenditure; and – other relevant cash inflows and outflows. Cash flow scenarios for a range of commodity prices and foreign exchange rates are assessed using internal and external market forecasts, and the present value of the forecast cash flows is determined utilising a pre-tax discount rate. The Group’s cash flows are most sensitive to movements in commodity price, expected quantities of ore reserves and mineral resources and key operating costs. In particular, CGO, MGO and FGO are most sensitive to expected quantities of ore reserves and mineral resources to be extracted and therefore the estimated future cash inflows resulting from the sale of product produced is dependent on these assumptions. Variations to the expected cash flows, and the timing thereof, could result in significant changes to any impairment losses recognised, if any, which in turn could impact future financial results. To the extent that capitalised mine development expenditure is determined not to be recoverable in the future, this will reduce profit in the period in which the Group makes this determination. Capitalised mine development expenditure is assessed for recoverability in a manner consistent with property, plant and equipment as described below. Refer to Note 2(o) for further discussion on the impairment assessment process undertaken by the Group. Provision for expected credit losses (ECLs) on trade receivables and other short-term receivables carried at amortised cost The Group uses a provision matrix to calculate ECLs for trade and other short-term receivables carried at amortised cost. The provision rates are based on days past due. The provision matrix is initially based on the Group’s historical observed default rates. The Group calibrates the matrix to adjust the historical credit loss experience with forward-looking information. For instance, if forecast economic conditions are expected to deteriorate over the next year, which can lead to an increased number of defaults, the historical default rates are adjusted. At every reporting date, the historical observed default rates are updated and changes in the forward-looking estimates are analysed. The assessment of the correlation between historical observed default rates, forecast economic conditions and ECLs is a key estimate. The amount of ECLs is sensitive to changes in circumstances and of forecast economic conditions. The Group’s historical credit loss experience and forecast of economic conditions may also not be representative of customer’s actual default in the future.