Mining investment decisions are difficult since decision analysis is often based on scarce information. The sources of uncertainty in large mining investment projects are particularly numerous and are present in all evaluation stages. Hence the feasibility decision for projects of this nature will largely depend on how well these sources of uncertainty are managed to achieve bankable risk levels. The risk associated to the construction stages of a mining project is particularly difficult to quantify,mainly because the large number of variables affecting constructive yields,and the complex interactions among constructive resources. This investigation focuses on developing quantitative simulation models and tools to increase the value of a mining project by means of an optimization of the preproduction equipment fleet. The models were validated through their application In the Chuquicamata Underground Mining Project.