Shovel-truck optimization study in an opencast mine - A queueing approach

Abstract

The shovel-truck combination is the versatile work horse in small as well as large opencast mining projects. The optimization of shovel-truck combination is imperative in order to increase productivity from this system. The optimization studies aim at eliminating the excess shovel or excess truck capacity in order to minimise the shovel and/or truck idling period. The present case-study is the approach of queueing theory to the optimization of shovel-truck combination in an Indian opencast mine. The formulation of appropriate queueing model has been undertaken and the (M/M/C); (FIFO/K/K) model has been adjudged to be the best model to suit the shovel-truck optimization problem. Relationships between the length of queues, waiting time in queue, utilisation of shovel, approximate output from the shovel-truck combination and the costs involved in the system are critically analysed with respect to variation in the number of trucks. The optimum total cost and the optimum number of trucks in the case-study are deduced from the proposed queueing model.