ABSTRACT
It is of vital importance in a mechanized open-pit mine, that each shovel or group of shovels has the correct number of trucks assigned, in order to obtain the best overall performance. The allocation problem must be continually dealt with, since the number of available trucks and shovels varies with time. Production can be restricted by either the trucks or the shovels. If production is restricted, then the unit production capacity would have to be reduced accordingly, to balance the system.
Deterministic evaluation of shovel-fleet production capacity is always over-rated, despite sound estimating methods. As operating costs and stripping ratio increase, it is imperative to reduce this margin of error in the estimation process. Statistical analysis indicates that ignoring the impact of fleet imbalance, leads to the over-rating of the system by up to 15 percent. The impact of fleet imbalance can be determined, in the long run, by a 'balancing efficiency factor'. This factor can be obtained by analysis of shovel and truck utilization. The present study deals with the fleet imbalance analysis of a shovel-truck fleet in a group of large mechanized, open-pit mines in India.
