Optimising the number of load-haul-dump machines in a Swedish mine by using queuing theory: A case study

ABSTRACT This paper discusses the determination of optimal number of Load-Haul-Dump (LHD) machines for a given mine using queuing theory model. The number of LHDs is determined by taking into account the performance of LHD, the performance of repairshop, and economic factors such as operators salary, maintenance cost, price of an LHD machine, etc. It is shown with example that queuing model can accurately calculate the probability of a given number of LHD machines for production. This paper also illustrates with an example that the number of LHD machines estimated by using queuing model is more accurate compare to the method using binomial distribution, etc. The example used in this paper is from a Swedish mine.