【作者】 周小庄；

【导师】 刘杰；

【作者基本信息】 同济大学 ， 管理科学与工程， 2007， 博士

【摘要】 库存是制造企业的一项巨大投资，控制库存成本对于企业具有重要意义。传统库存成本控制方法是订货点法，它是以高库存量为基础，不能实现对库存成本的进一步控制，而JIT方法可以弥补它的不足。 JIT(Just in time，准时制)的核心思想是“非必要，勿生产”，JIT库存是JIT思想在库存管理中的应用，是JIT生产在库存管理中的延伸，是JIT生产对库存管理的必然要求。JIT库存具有小批量供应、库存低甚至为零的特点。 在给企业带来经济效益的同时，JIT库存还需要对以下问题进行研究：(1)需求不确定、供应故障情形下的安全库存量的设定问题；(2)小批量供应的合理性问题；(3)JIT库存中需求随机的经济订货批量的设定问题；(4)多品种库存提前期的平衡问题。 针对以上问题，论文主要采用定量分析的研究手段，提出了库存成本优化方法，通过实证检验了研究成果的有效性，研究成果对于完善JIT理论，指导JIT实践均具有重要意义。论文研究的主要内容如下： 在报童模型基础上，引入供应故障导致的不确定因素，在需求随机、供应故障导致部分缺货的前提下，建立了安全库存优化模型，分析得出了供应产品的缺货数量期望值，在平衡库存的存储成本和缺货成本的基础上确定了安全库存量。 在基本EOQ模型中引入物流成本因素，量化分析了异地和本地两种园区供应方式下的经济订货批量，进而论证了以下结论：园区供应方式下的小批量是经济订货批量；园区供应方式可以解决小批量供应导致的物流规模的不经济问题。并讨论了生产需求不确定的情形，在假设需求分别服从指数分布和正态分布的基础上，扩展了基本EOQ模型，得出了JIT方式下的经济订货批量。 在分析提前期与库存成本的关系基础上，论证了以下结论：在提前期网络计划图中，只要存在非关键路径，供应链库存成本就不是最优成本。在提前期确定和不确定两种情形下，给出了合理调度供应链各工作环节中的时间资源，优化库存成本的方法。 最后，给出了研究成果应用于实际库存对象的实证。更多还原

【Abstract】 The inventory is huge investment for manufacturing enterprises, therefore, to control inventory cost plays an important role in corporation management. OP (Order Point) is a traditional measure to control the inventory. However, it is based on high stock quantity which makes it difficult to implement further control. Fortunately, JIT can make up this shortage.The key idea of JIT (Just In Time) is "no need, no production". JIT inventory is the application extension and requirement of JIT production with the characters of small- batches supply and low even zero stock.With the benefit to enterprises, JIT inventory should be carried out the following research: The enactment of safety stock on the condition of indetermination need and supply breakdown; The rationality of small-batched supply; The enactment of economic order quantity based on random need; The balance of lead time of various stocks.Focusing on the above-mentioned problems, in the dissertation, the methods of inventory cost optimization has been worked out by the research of quantitative analysis with relevant validity demonstration which is significant to perfect JIT theory and guide JIT practice. The main content of the dissertation contains:Based on Newboy model, introducing indetermination factors caused by supply breakdown; analyzing expectation value of supply products out of stock on the condition of random need, partly being out of stock caused by supply breakdown; balancing storage cost and cost out of stock and building up the optimization model on safety stock.Introducing logistics cost factor in the Basic EOQ model, analyzing economic order quantity respectively with foreign and local industrial park supply and eventually drawing the following conclusion: ①The small-batches of industrial park supply is an economic order quantity. ②Industrial park supply can solve the problem of noneconomic logistic scale caused by small-batches supply.Extending as well classical EOQ model under the condition that demand obeysexponent distribution and normal distribution to acquire economic order quantity with JIT method.Analyzing and demonstrating the below conclusion: inventory cost of supply chain would be not the lowest if only a non- critical path exists in lead time network program. Proposing an optimization method of inventory cost by scheduling rationally time resource in all working sectors of supply chain under the condition of determinate and indeterminate lead time.Finally, giving the demonstration by applying the research result to an actual inventory object.更多还原