Revenue Factor (RF) in open pit optimization is a multiplier applied to the base commodity price to simulate different economic conditions; For example, an RF of 1.0 uses the actual price, while values below or above represent lower or higher price scenarios. When optimization is run at multiple RF values, it generates a series of pit shells that increase in size as RF increases, because more material becomes economically mineable. These shells are called nested pits since each smaller pit lies entirely within the larger ones. Nested pits represent different economic outcomes, allowing Engineers to assess project sensitivity to price changes where large variations indicate higher risk and to identify stable, high-value zones. They are also used to design mining stages (pushbacks), enabling a phased approach that improves cash flow, reduces initial capital requirements, and supports efficient long-term mine planning.