这里所说的生产汽车备用量是指处于随机故障修理的汽车数。露天矿总的备用车辆数除生产汽车备用量外,还应包括处于计划检修、保养的汽车数。美国凯萨公司为我国司家营铁矿所做的设计中,把单台汽车的完好与故障视为贝努里试验结果。并假定单台汽车的完好率为0.85,不可使用的概率为0.15。按二项分布 The production car spares here refers to the number of cars that are undergoing random fault repairs. The total number of spare vehicles in the open pit should include the number of vehicles under planned overhaul and maintenance in addition to the production of spare vehicles. The design of the U.S. Caesar Company for the iron ore mine in Sijiaying of our country regards the intactness and failure of a single car as the result of Benouri test. And assume that a single car intact rate of 0.85, the probability of not using 0.15. According to binomial distribution