Case studies based on various recoverable resource modelling techniques have been derived using typical feasibility study or new mine drilling data configurations that were drawn from a massive production database. The corresponding recoverable and non-recoverable resources from the various techniques are then analysed using the open pit Whittle optimisation process. The results were then compared with the historical corresponding grade control and production data results to determine the efficiencies of the approaches and the validity of the recoverable/non-recoverable mineral resource estimates for mine planning and financial forecasts (including Cash Flows etc.). The paper further discusses the corresponding orebody and mine planning as well as financial risks. The study shows that the localised direct and somewhat more straight forward recoverable model approach if applied efficiently can provide an equally useful tool for computing recoverable resources for mine planning and financial forecasts, when compared to the indirect approach as presently in use. The paper demonstrates that any capital-intensive mining project (or mine extensions) decisions made on the basis of any of the smoothed non-recoverable estimates will tend to misrepresent the economic value of the project or operation.