Analysis of an inventory system with emergency ordering option at the time of supply disruption
研究企业在面临随机需求和供应中断时，通过在中断时刻根据库存水平发出紧急订单来降低成本的库存策略，并利用连续时间马尔可夫链模型求解最优参数。
Abstract This paper studies a continuous-review stochastic inventory problem for a firm facing random demand and random supply disruptions. The supplier experiences operational ( on ) and disrupted ( off ) periods with exponentially distributed durations. The firm adopts an order-up-to level policy during the on period and additionally can release an emergency order based on the inventory level just before disruption. This inventory policy is described by a continuous-time Markov chain model. We analyze the model for two different lead time scenarios and suggest solution approaches yielding the optimal policy parameters. In a numerical study, we explore the value of exercising such a policy and show that an emergency ordering opportunity at the disruption time brings substantial cost savings in cases with high lost sales cost, long off period, and low percentage of supplier’s availability.