two-bin inventory system

Transportation and inventory solve the problems of time separation and place separation between the supplier and the vendor respectively. They are the main function factors that create place value and time value through logistics and two essential links in logistics system.

物流中的采购、库存及运输等环节，分别解决了供给者与需求者之间场所和时间的分离，分别是物流创造场所价值和时间价值的主要功能因素，是物流系统中的关键环节。

Then, according to the current researches, the models of two-stage inventory system and three-stage inventory system are perfected respectively, through considering delay in payments, deterioration of physical goods, decreasing function of waiting time, varying demand.

然后，分别针对现有的两阶段和三阶段库存模型，将延期支付、产品退化、欠拨情况以及随机性需求函数纳入到模型中来考虑，通过分析，推导出相应的数学模型。