What is the difference between a phase, a pushback and a schedule?
A phase (nested pit) is a Lerchs Grossman ultimate pit obtained for specific block economic values. The only criterion used to obtain a phase is the maximization of cash flow. A pushback is a pit that in addition to maximizing the cash flow, also satisfies a number of practical mining requirements including minimum size and access space. Unlike a phase, a pushback always consist of spatially connected blocks. A schedule is a sequence of pits (equivalently, blocks) that meet user defined targets and thus gives the best picture of optimal ways of developing the mine.
