Industrial Engineering and Operations Research, Columbia University, 500 West 120th Street, New York, NY 10027, United States.
Vaccine. 2012 Sep 21;30(43):6175-9. doi: 10.1016/j.vaccine.2012.07.066. Epub 2012 Aug 5.
The U.S. has experienced many major interruptions of its pediatric vaccine production in the past decade. The Centers for Disease Control and Prevention (CDC) copes with these shortages by building a national stockpile of pediatric vaccines, which it makes accessible to the public in the event of a shortage. The management of this stockpile is difficult due to limited production capacity and long and unpredictable production interruptions. In this paper, we address policies for managing the stockpile. We provide sufficient conditions for the optimal policy to be a modified state-dependent base-stock policy, with the base-stock level decreasing in the pipeline inventory. Since the optimal policy is in general difficult to evaluate, we derive bounds on the optimal decision in each period. We develop an efficient policy that performs on average within 1% of optimality in simulations. We show that stocking the same supply of vaccine of every type can be over-conservative in some cases, and inadequate in others by large factors. We also quantify the substantial reduction in inventory level that can be achieved when there are multiple suppliers in the market.
美国在过去十年中经历了多次儿科疫苗生产的重大中断。疾病控制与预防中心 (CDC) 通过建立国家儿科疫苗储备来应对这些短缺，以便在短缺时向公众提供疫苗。由于生产能力有限，以及生产中断时间长且不可预测，因此管理这种储备具有挑战性。在本文中，我们探讨了管理该储备的政策。我们提供了充分的条件，以使最优政策成为一种修正的状态相关基本库存政策，其中基本库存水平随管道库存而减少。由于最优政策通常难以评估，因此我们在每个时期推导出最优决策的上下界。我们开发了一种有效的策略，在模拟中平均表现优于最优策略的 1%。我们表明，在某些情况下，为每种类型的疫苗储备相同的供应可能过于保守，而在其他情况下则可能严重不足。我们还量化了当市场上有多个供应商时可以实现的库存水平的大幅降低。
