Mining is a high risk, high capital and potentially high reward undertaking. A large proportion of the risk comes from a lack of definition of the orebody (which also provides some of the potential) and the unpredictable nature of the market. This makes the planning process difficult but encourages the development of a robust yet flexible mining system. The system should be capable of absorbing some deviation from the anticipated concept without a significant impact on profitability. The mine planning process tends to consist of a series of related but discrete stages. For instance, the pit shells are designed, a schedule for the pit shells is created, a plant fleet is chosen to achieve the schedule and a financial analysis is carried out on that scenario. It is likely a few iterations are carried out using various mill throughputs to produce a favoured financial result. The problem is that handing results from stage B' for use in C' doesn't encourage a flexible system. C' is likely to be built for exactly B'. Unfortunately, in mining, A' (the orebody) has the highest potential for variability and impacts everything else downstream. D' the market also has high potential for unplanned variability. These variations can spread and reverberate' through the whole mine process. For example an unexpected increase in ore oversize impacts all downstream mine processes to the primary crusher which may in turn create problems back upstream' by restricting throughput rate. Also an unexpected drop in demand or price could require modifications to the planned production rates. This paper looks at how mining process simulation can be used to support the development of strategies to counteract unforseen circumstances or alter production to match fluctuations in demand and price.