Considering the fact that data estimates are subjected to uncertainty, the initial basic analysis of the gold project should be done considering two positions, the first one is based on an assumed certainty and the second consider an assumed risk. In the first case, each economical analysis is done considering one set of selected data, which may represent the average estimates and minimum expected conditions. The critical data is identified by performing successive calculations, varying the data used. Such studies are known as sensitivity analyses and isolate the economic effect of several uncertainties and help the allocation of future efforts toward improving the overall exactitude of the analysis.
When the analysis considers an assumed risk, it is examined the interactive effect of the current uncertainties by qualitative assigning probability distributions to each data. These probability distributions indicate the currently appraised opportunity that a given numerical value will prove to be true. The corresponding procedure, risk analysis consists of studying many individual financial analyses, each analysis being based on randomly selected numerical values from the probabilistic distributions and the result is a numerical presentation of the uncertainty. Nevertheless, care must be considered in the interpretation of the results. Basically, the advantage of this procedure is the direct measurement of economic uncertainty produced by the interaction of uncertain estimates.
It is import to study the economy of the gold project by accomplishing sensitivity and risk analyses. Considering the principle of assumed uncertainty, estimates of the evaluation factors appropriate to gold ore target and mining method are key aspects of the analysis. The analyst processes the information and gets a first estimate based on evaluation factors, followed by evaluation constants, mine life summary and average unit costs which may be used as a starting point for the detailed study of the economics of the project. Discounted cash flow rate of return, the hypothetical management criterion indicates if the deposit is adequately profitable. In summary, the project analyst takes single values for each evaluation factor and yield a single result. Successive calculations are made to test the sensitivity of uncertain factor estimates.