Due to highly competitive international coal markets, Stockton mine is bound to produce very high quality coals consistently if it is to maintain and expand its market share._x000D_
The nature of the deposit is such that coals from various source pits are blended in differing proportions to meet the various coal quality specifications of the customer. The complexity arises due to quality variation within the seam both horizontally and vertically and the fact that up to six different products with completely different quality specifications may have to be produced._x000D_
With increasing demand for this rare product and with CoalCorp eager to meet this demand comes the requirement for computer methods to handle this highly complex problem of both modelling and scheduling.