Simulation modelling has long been used to support operations strategy decisions in the mining industry. Recently, the commodity cycle and push for lower costs has driven efforts to improve operations efficiency. The use of simulation has typically been challenging in the operational time horizon due to the difficulty of initializing the system state and the sensitivity of the results to initial conditions. However, a recent explosion in data availability has made it feasible to know, in real time, the location of each piece of equipment in the fleet, what it is carrying and where it is going. This makes it possible to simulate and predict production performance within a shift and to allow testing of what-if scenarios to improve operations efficiency. In this case study we describe the approach taken, the application of simulation for short-term forecasting and the challenges faced implementing this for a global mining company.