第九章库存决策.pptVIP

9.8渠道中库存（Pipeline Inventories） 渠道中库存就是置于运输设备上，在存储点之间移动的在途库存。对渠道中库存的管理就是对在途时间的控制，主要通过选择运输服务进行。 * 第九十四页，共一百三十三页。 CR (2004) Prentice Hall, Inc. 9.7.4需求不确定条件下的定期盘点模型 Periodic review control with demand uncertainty 按预先确定的周期（T)核查某种产品的库存。盘点后的订货量就是最大值（M)与盘点时所持有的库存量之差。因此可以通过设定T*和M*控制库存。 Given: d = 50 units/week C = $5/unit sd = 10 units/week LT = 3 weeks I = 10%/year P = 0.99 S = $10/order k = $2/unit Good method for products: Of low value That are purchased from the same vendor Having economies of scale in production, purchasing, and transportation 9-38 * 第六十二页，共一百三十三页。 9-39 Q1 Stock level reviewed T T LT LT Order received Q2 M q 0 Quantity on hand Time M = maximum level最高库存 M - q = replenishment quantity补货量 LT = lead time提前期 T = review interval盘点周期 q = quantity on hand持有库存量 Qi = order quantity订购量 ~ 单一产品定期盘点Periodic Control for a Single Item 盘点时库存 * 第六十三页，共一百三十三页。 CR (2004) Prentice Hall, Inc. Estimate Q* from the EOQ formula as if under demand certainty conditions. Recall that this is Q* = 322 units. Now, T* = Q*/d = 322/50 = 6.4 weeks Construct the demand-during-lead-time-plus-order-cycle-time distribution. T is order review time Periodic Review (Cont’d) * 第六十四页，共一百三十三页。 CR (2004) Prentice Hall, Inc. Periodic Review (Cont’d) P DD(T* + LT) X = d(T* + LT) MAX s′ Z(s′) * 第六十五页，共一百三十三页。 Periodic Review (Cont’d) where Find MAX MAX = d(T* + LT) + z(s’) = 50(6.4 + 3) + 2.33(30.66) = 470 + 71.44 = 541 units Rule Review the inventory every 6.4 weeks and place an order for the difference between the MAX level of 541 units and the quantity on hand + quantity on order – backorders. CR (2004) Prentice Hall, Inc. 9-42 * 第六十六页，共一百三十三页。 CR (2004) Prentice Hall, Inc. Periodic Review (Cont’d) 总相关成本 The total relevant cost for this design is: TC = DS/Q + ICQ/2 + ICr + ks’(D/Q)E(z) = 2600(10)/322 + (.10)(5)(322/2) + (.10)(5)(71) + 2 (30.66)(2600/322)(.003