Introduction
Truck haulage is the most widely used means of transportation in an open pit mining operation, but is often the single most expensive process in a truck-shovel mining system. According to Michaelson (1974), truck-fleet productivity in open pit copper mines has the lowest improvement rate among the three major unit operations drilling, loading and hauling In addition, trucks require much labor, high maintenance and relatively frequent replacement making them sensitive to inflation. Most operating shovels experience either some insufficient or excessive truck capacity or a combination of both in truck-shovel mining system. To meet required production with increasing depth of pit or changing ore-waste stripping ratios, additional equipment is required each year. As a result management is faced with the problem of buying additional trucks or shovels if there is an improper balance of equipment in the mining operation. This problem usually results from inadequate use of haulage resources. Recent increases of the energy cost together with projected future increases will further increase truck-fleet capital and operating costs in the future. Therefore, it seems appropriate to test any strategy for optimizing truck-fleet performance...
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