Proceedings of 5th European Business Research Conference 10 - 11 September 2015, St. Regis Hotel, Rome, Italy, ISBN: 978-1-922069-83-2 Evaluation of Cu-Ni Mine Expansion Project in the Stratified State Aggregation Method: Real Option Analysis Dineo Florence Sefemo* and Tsuyoshi Adachi** Mining projects are multistaged investments that require management decision making to invest either now or in future when some parameters of the projects are being resolved. Most commonly the binomial tree option pricing is used to price American type options under Real Option Valuation (ROV). The difficulties of this method is the inability to handle the projects multiple sources of uncertainties and accurate simulations. We therefore present the developed numerical Monte Carlo simulation, the stratified state aggregation method to value the expansion option of Selebi Central Cu-Ni project in BCL mine, Botswana under ROV. The metal price market and geological uncertainty are modelled together to estimate the net present and expansion option values which includes the value of management flexibility. This method treats the project from current operating to expanded state within the set development period with decision making to continue from one state to the other. The results show significantly improved expected net present value and expansion option value with in cooperation of multiple key principal uncertainties for this project. The expansion option payoff values and optimal investment timing under real options analysis are determined with recommendation for future execution of Selebi Central at the calculated expansion option value. Management Keywords: Stratified State Aggregation, Real Options, Optimal Investment Timing, Binomial Option Pricing * Miss Dineo Florence Sefemo, Graduate School of Engineering and Resources Sciences, Akita University.11 Tegata - Gakuenmachi Akita City, 010-0825, Japan. Email : dineo.sefemo@yahoo.com ** Prof. Tsuyoshi Adachi, Faculty of International Resource Sciences, Akita University, Akita, 0101-0825, Japan. Email : adachi.tgipc.akita-u.ac.jp