p11 managing supply chain inventory
Supply Chain Management
Supply Chain Management供应链的概念要想打造一流的供应链，需要企业全民参与。
因为供应链本身就是一个跨职能部门的概念，企业所有的员工都得了解供应链，并在建设高效供应链的过程中提供支持。
对于企业领导人来说，要在组织中普及有关供应链的知识，帮助员工更清楚地了解自己对成功实施供应链的重要影响，以及每个部门、每个人所扮演的角色。
有这样一个概念：理想情况下，如果公可上下都了解并应用它，便能提升企业的运营效率和财务表现，成为公司竞争优势的新来源；但实际情况中，大部分员工只是耳闻，不知其详，另外一些了解的人对它的解释却是各执一端。
这个概念是什么呢？就是供应链管理（SCM）。
大部分专家很可能对供应链的基本组成甚至定义已经达成了一致。
然而，许多其他部门的经理却并不十分清楚供应链经理在做些什么，对供应链能够带来的好处也并不称道。
可想而知，这些经理们对于自己能为供应链项目的成功实施贡献些什么也是浑然不晓。
供应链知识需要普及供应链经理的工作之所以这么难以被众人理解，部分是因为对"供应链"这个概念的看法和定义太多太杂。
供应链研究的权威、美国密歇根州立大学的蒙兹卡教授（Robert Monczka）指出，关于供应链的说法，一个组织里甚至都可能有上好几种。
下面的例子向你说明了这种情况可能带来的负面结果。
一家消费品企业的高管们组建了一个团队，来改进供应链，但最近他们发现收效甚微。
来自外部的评估结果是：团队成员并没有充分了解供应链管理的概念和目标。
他们没能站在公司整体的高度把握公司究竟须要达到什么目的，或者没能把握企业从垂直结构（职能型）向水平结构（跨职能）的转变需要做哪些事情。
团队的一些成员也承认，他们的视野受到了传统的职能型理念的束缚。
而当他们要跨部门或跨职能边界寻求效率改进的机会时，却总会遭遇到来自职能部门经理的直接阻挠。
这个例子说明，必须在整个企业内部普及供应链常识。
其他部门的经理和团队也须要了解供应链的概念，因为在支持供应链的活动和流程上，他们是不可缺少的一分子。
（完整版）供应链管理第三版Unit11习题与答案
（完整版）供应链管理第三版Unit11习题与答案Chapter 11Managing Uncertainty in the Supply Chain: Safety Inventory True/False1. Safety inventory is inventory carried for the purpose of satisfying demand thatexceeds the amount forecasted for a given period.Answer: TrueDifficulty: Moderate2. Safety inventory is carried because demand forecasts are accurate and aproduct shortage may result if the forecast demand exceeds the actual demand.Answer: FalseDifficulty: Moderate3. Raising the level of safety inventory increases product availability and thus themargin captured from customer purchases.Answer: TrueDifficulty: Moderate4. Raising the level of safety inventory increases inventory holding costs.Answer: TrueDifficulty: Easy5. Carrying excessive inventory can help counter demand volatility when newproducts come on the market.Answer: FalseDifficulty: Moderate6. The appropriate level of safety inventory is determined by the uncertainty of bothdemand and supply and the desired level of cycle inventory.Answer: FalseDifficulty: Moderate7. As the uncertainty of supply or demand grows, the required level of safetyinventories increases.Answer: TrueDifficulty: Moderate8. As the desired level of product availability increases, the required level of safetyinventory decreases.Answer: FalseDifficulty: Easy9. Lead time is the gap between when an order is placed and when it is received.Answer: TrueDifficulty: Easy10. The coefficient of variation measures the size of the relative certainty of cycleinventory.Answer: FalseDifficulty: Easy11. Product availab ility reflects a firm’s ability to fill a customer order out of availableinventory.Answer: TrueDifficulty: Moderate12. Order fill rate is the fraction of product demand that issatisfied from product ininventory.Answer: FalseDifficulty: Moderate13. Product fill rate is the fraction of product demand that is satisfied from product ininventory.Answer: TrueDifficulty: Moderate14. The distinction between product fill rate and order fill rate is significant in a singleproduct situation.Answer: FalseDifficulty: Hard15. Tracking order fill rates is important when customers place a high value on theentire order being filled simultaneously.Answer: TrueDifficulty: Easy16. With continuous review, inventory is continuously tracked and an order for a lotsize Q is placed at regular intervals of time.Answer: FalseDifficulty: Hard17. With periodic review, inventory status is checked at regular intervals and an orderis placed to raise the inventory level to a specified threshold.Answer: TrueDifficulty: Hard18. The expected shortage per replenishment cycle(ESC) isthe average units ofdemand that are satisfied from inventory in stock per replenishment cycle.Answer: FalseDifficulty: Hard19. A shortage occurs in a replenishment cycle only if the demand during the leadtime exceeds the ROP.Answer: TrueDifficulty: Moderate20. The fill rate increases and the cycle service level decreases as the safetyinventory is increased.Answer: FalseDifficulty: Moderate21. For the same safety inventory, an increase in lot size increases the fill rate butnot the cycle service level.Answer: TrueDifficulty: Hard22. The required safety inventory grows rapidly with a decrease in the desiredproduct availability.Answer: FalseDifficulty: Easy23. The required safety inventory increases with an increase in the lead time and thestandard deviation of periodic demand.Answer: TrueDifficulty: Easy24. A goal of any supply chain manager is to reduce the level of safety inventoryrequired regardless of the affect product availability.Answer: FalseDifficulty: Easy25. In most supply chains, the key to reducing the underlying forecast uncertainty isto link all forecasts throughout the supply chain to customer demand data.Answer: TrueDifficulty: Moderate26. A reduction in supply can help dramatically reduce safety inventory requiredwithout hurting product availability.Answer: FalseDifficulty: Moderate27. Aggregation reduces the standard deviation of demand only if demand acrossthe regions being aggregated is not perfectly positively correlated.Answer: TrueDifficulty: Moderate28. In case demand in different geographical regions is about the same size andindependent, aggregation increases safety inventory by the square root of thenumber of areas aggregated.Answer: FalseDifficulty: Moderate29. If aggregation reduces the required safety inventory fora product by a smallamount, it may be best to carry the product in multiple decentralized locations to reduce response time and transportation cost.Answer: TrueDifficulty: Moderate30. The lower the coefficient of variation of an item, the greater the reduction insafety inventories as a result of centralization.Answer: FalseDifficulty: Hard31. Manufacturer-driven substitution increases overall profitability for themanufacturer by allowing some aggregation of demand, which reduces theinventory requirements for the same level of availability.Answer: TrueDifficulty: Moderate32. Postponement allows the supply chain to delay product differentiation, whichresults in disaggregating most of the inventories in the supply chain.Answer: FalseDifficulty: Moderate33. Periodic review policies require more safety inventory than continuous reviewpolicies for the same level of product availability.Answer: TrueDifficulty: Easy34. When using a continuous review policy, a manager has toaccount for theuncertainty of demand during the lead time and the review interval.Answer: FalseDifficulty: EasyMultiple Choice1. Inventory carried for the purpose of satisfying demand that exceeds the amountforecasted for a given period isa. cycle inventory.b. demand inventory.c. safety inventory.d. security inventory.e. all of the aboveAnswer: cDifficulty: Easy2. Safety inventory is carried becausea. demand forecasts are accurate.b. demand forecasts are uncertain.c. adequate supplies are available.d. excess product was manufactured.e. forecast demand exceeds the actual demand.Answer: bDifficulty: Moderate3. The trade-off that a supply chain manager must consider when planning safetyinventory isa. increasing product availability versus increasing inventory holding costs.b. decreasing product availability versus decreasinginventory holding costs.c. increasing product availability versus raising the level of safety inventory.d. decreasing product availability versus decreasing the level of safetyinventory.e. none of the aboveAnswer: aDifficulty: Moderate4. The issue of product availability and the level of safety inventory is particularlysignificant in industries wherea. product life cycles are short and demand is stable.b. product life cycles are short and demand is very volatile.c. product life cycles are long and demand is stable.d. product life cycles are long and demand is very volatile.e. a and b onlyAnswer: bDifficulty: Moderate5. A key to success at which company has been its ability to provide a high level ofproduct availability to customers while carrying very low levels of safety inventory in its supply chain?a. Compaqb. Hewlett-Packardc. Delld. Packard-Belle. all of the aboveAnswer: cDifficulty: Moderate6. What key question(s) need(s) to be considered when planning safety inventoryfor any supply chain?a. What is the appropriate lead time to establish?b. What is the appropriate level of safety inventory to carry?c. What actions can be taken to improve product availability while reducingsafety inventory?d. a and b onlye. b and c onlyAnswer: eDifficulty: Moderate7. The appropriate level of safety inventory is determined bya. the uncertainty of both demand and supply.b. the desired level of product availability.c. the desired level of cycle inventory.d. the processes in a supply chain are divided into 2 categories dependingall of the abovee. a and b onlyAnswer: eDifficulty: Moderate8. As the uncertainty of supply or demand grows, the required level of safetyinventoriesa. decreases.b. increases.c. remains stable.d. both a and be. none of the aboveAnswer: bDifficulty: Moderate9. As the desired level of product availability increases, the required level of safetyinventorya. decreases.b. increases.c. remains stable.d. both a and be. none of the aboveAnswer: eDifficulty: Moderate10. Lead time is the gap betweena. when an order is placed and when it is received.b. when an order is received and when it is put away.c. when an order is received and when it is used.d. when an order is acknowledged and when it is received.e. none of the aboveAnswer: aDifficulty: Easy11. The coefficient of variation measuresa. the accuracy of the demand forecast.b. the size of the uncertainty relative to demand.c. the relevance of cycle inventory to demand.d. the relative certainty of the forecast.e. none of the aboveAnswer: bDifficulty: Moderate12. Which of the following is not a measure of product availability?a. customer fill rateb. product fill ratec. order fill rated. cycle service level(CSL)e. none of the aboveAnswer: aDifficulty: Moderate13. The fraction of orders that are filled from available inventory is thea. customer fill rate.b. product fill rate.c. order fill rate.d. cycle service level(CSL).e. none of the aboveAnswer: cDifficulty: Easy14. The fraction of product demand that is satisfied from product in inventory is thea. customer fill rate.b. product fill rate.c. order fill rate.d. cycle service level(CSL).e. none of the aboveAnswer: bDifficulty: Easy15. The fraction of replenishment cycles that end with all the customer demand beingmet is thea. customer fill rate.b. product fill rate.c. order fill rate.d. cycle service level(CSL).e. none of the aboveAnswer: dDifficulty: Easy16. If a customer order arrives when product is not availablea. a sale results.b. the retailer allocates product to the customer.c. a stockout results.d. the order is filled from safety inventory.e. none of the aboveAnswer: cDifficulty: Moderate17. The distinction between product fill rate and order fill rate isa. not significant in a single product situation.b. significant in a single product situation.c. not significant when a firm is selling multiple products.d. significant when a firm is selling multiple products.e. both a and dAnswer: aDifficulty: Moderate18. A replenishment policya. consists of decisions regarding when to reorder and how much to reorder.b. determines the cycle and safety inventories along with the fr and the CSL.c. may take several forms.d. All of the above are true.e. None of the above are true.Answer: dDifficulty: Moderate19. A company that tracks inventory and places an order fora lot size Q when theinventory declines to the reorder point (ROP) is usinga. continuous review.b. daily review.c. occasional review.d. periodic review.e. none of the aboveAnswer: aDifficulty: Easy20. A company that checks inventory status at regular periodic intervals and placesan order to raise the inventory level to a specified threshold is usinga. continuous review.b. daily review.c. occasional review.d. periodic review.e. none of the aboveAnswer: dDifficulty: Moderate21. Which of the following is correct?a. Average inventory = cycle inventory + safety inventoryb. Average inventory = cycle inventory - safety inventoryc. Average inventory = cycle inventory x safety inventoryd. Average inventory = cycle inventory / safety inventorye. none of the aboveAnswer: aDifficulty: Easy22. The expected shortage per replenishment cycle(ESC) isa. the units of demand that are not satisfied from inventory in stock in agiven replenishment cycle.b. the units of demand that are satisfied from inventory in stock in a givenreplenishment cycle.c. the average units of demand that are not satisfied from inventory in stockper replenishment cycle.d. the average units of demand that are satisfied from inventory in stock perreplenishment cycle.e. none of the aboveAnswer: cDifficulty: Moderate23. The product fill rate (fr)is thus given bya. fr = 1 –ESC/Q + (Q – ES C)/Q.b. fr = 1 –ESC/Q –(Q – ES C)/Q.c. fr = 1 + ESC/Q = (Q + ES C)/Q.d. fr = 1 –ESC/Q = (Q – ES C)/Q.e. none of the aboveAnswer: dDifficulty: Hard24. Given a lot size of Q (which is also the average demandin a replenishment cycle)a. the fraction of demand lost is thus ESC + Q.b. the fraction of demand lost is thus ESC –Q.c. the fraction of demand lost is thus ESC/Q.d. the fraction of demand lost is thus ESC x Q.e. none of the aboveAnswer: cDifficulty: Hard25. A shortage occurs in a replenishment cyclea. only if the demand during the lead time exceeds the ROP.b. only if the demand during the lead time is less than the ROP.c. only if the demand during the lead time exceeds the average demand.d. only if the demand during the lead time is less than the average demand.e. none of the aboveAnswer: aDifficulty: Moderate26. As the safety inventory is increaseda. fill rate increases and cycle service level decreases.b. fill rate decreases and cycle service level increases.c. both fill rate and cycle service level increase.d. both fill rate and cycle service level decrease.e. none of the aboveAnswer: cDifficulty: Moderate27. For the same safety inventory, an increase in lot sizea. decreases the fill rate but not the cycle service level.b. increases the fill rate but not the cycle service level.c. decreases both the fill rate and the cycle service level.d. increases both the fill rate and the cycle service level.e. none of the aboveAnswer: cDifficulty: Hard28. The expected shortage per replenishment cycle is shown asa. ESC = (1 + fr)Q.b. ESC = (1 –fr)Q.c. ESC = (1 + fr)/Q.d. ESC = (1 –fr)/Q.e. none of the aboveAnswer: bDifficulty: Hard29. The required safety inventorya. grows rapidly with a decrease in the desired product availability.b. grows rapidly with an increase in the desired product availability.c. decreases with an increase in the desired product availability.d. remains stable with an increase in the desired product availability.e. none of the aboveAnswer: bDifficulty: Moderate30. The required safety inventorya. increases with an increase in the lead time and thestandard deviation ofperiodic demand.b. decreases with an increase in the lead time and the standard deviation ofperiodic demand.c. remains stable with an increase in the lead time and the standarddeviation of periodic demand.d. increases with a decrease in the lead time and the standard deviation ofperiodic demand.e. none of the aboveAnswer: dDifficulty: Moderate31. A goal of any supply chain manager is toa. increase the level of safety inventory required in a way that does notadversely affect product availability.b. increase the level of safety inventory required regardless of the effect onproduct availability.c. reduce the level of safety inventory required regardless of the effect onproduct availability.d. reduce the level of safety inventory required in a way that does notadversely affect product availability.e. none of the aboveAnswer: dDifficulty: Moderate32. Which of the following is not an approach to reduce the level of safety inventoryrequired in a way that does not adversely affect product availability?a. Reduce the supplier lead time.b. Reduce the underlying uncertainty of demand.c. Reduce the cost of material coming from suppliers.d. All of the above are approaches.e. None of the above are approaches.Answer: cDifficulty: Hard33. Often, safety inventory calculations in practicea. do not include any measure of supply uncertainty, resulting in levels thatmay be higher than required.b. do not include any measure of supply uncertainty, resulting in levels thatmay be lower than required.c. include measures of supply uncertainty, resulting in levels that may behigher than required.d. include any measures of supply uncertainty, resulting in levels that maybe lower than required.e. None of the above are accurate.Answer: bDifficulty: Hard34. Aggregation reduces the standard deviation of demanda. only if demand across the regions being aggregated is perfectly positivelycorrelated.b. only if demand across the regions being aggregated is not perfectlypositively correlated.c. even if demand across the regions being aggregated is not perfectlypositively correlated.d. whenever demand across the regions being aggregated is not perfectlypositively correlated.e. All of the above are accurate.Answer: bDifficulty: Hard35. If the number of independent stocking locations decreases by a factor of n, theaverage safety inventory is expected toa. decrease by a factor of √n.b. decrease by a factor of n.c. increase by a factor of √n.d. increase by a factor of n.e. None of the above are accurate.Answer: aDifficulty: Moderate36. Which of the following is not a major disadvantage of aggregating all inventory inone location?a. Increase in forecast accuracy of customer demand.b. Increase in response time to customer order.c. Increase in transportation cost to customer.d. All of the above are disadvantages.e. All of the above are advantages.Answer: aDifficulty: Easy37. Which of the following is not a method by which a supply chain can extract thebenefits of aggregation without having to physically centralize all inventories inone location?a. information centralizationb. specializationc. product substitutiond. component differentiatione. postponementAnswer: dDifficulty: Moderation38. Which approach to aggregation requires an information system that allowsaccess to current inventory records from each location?a. information centralizationb. specializationc. product substitutiond. component commonalitye. postponementAnswer: aDifficulty: Easy39. Which approach to aggregation would stock the fast-moving items atdecentralized locations close to the customer and slow-moving items at acentralized location?a. information centralizationb. specializationc. product substitutiond. component commonalitye. postponementAnswer: bDifficulty: Moderate40. The use of one product to satisfy demand for a different product isa. information centralization.b. specialization.c. product substitution.d. component commonality.e. postponement.Answer: cDifficulty: Easy41. Which use of common components in a variety of products has been a veryeffective supply chain strategy to exploit aggregation and reduce componentinventories?a. information centralizationb. specializationc. product substitutiond. component commonalitye. postponementAnswer: aDifficulty: Easy42. The ability of a supply chain to delay product differentiation or customization untilcloser to the time the product is sold isa. information centralization.b. specialization.c. product substitution.d. component commonality.e. postponement.Answer: eDifficulty: Moderate43. Which approach to aggregation has the goal of moving product differentiation asclose to the pull phase of the supply chain as possible?a. information centralizationb. specializationc. product substitutiond. component commonalitye. postponementAnswer: eDifficulty: Moderate44. Periodic review policies for inventory replenishment require safety inventory tocover demand duringa. lead time only.b. the review interval only.c. both lead time and the review interval.d. neither lead time or the review interval.e. lead time when it exceeds the review interval.Answer: cDifficulty: Moderate45. Continuous review policies for inventory replenishment require safety inventory tocover demand duringa. lead time only.b. the review interval only.c. both lead time and the review interval.d. neither lead time or the review interval.e. lead time when it exceeds the review interval.Answer: aDifficulty: Moderate46. Periodic review policies requirea. more safety inventory than continuous review policies for the same levelof product availability.b. less safety inventory than continuous review policies for the same level ofproduct availability.c. the same safety inventory as continuous review policies for the samelevel of product availability.d. no more safety inventory than continuous review policies for the samelevel of product availability.e. none of the aboveAnswer: aDifficulty: Moderate47. All inventory between a given stage in the supply chain and the final customer iscalled thea. cycle inventory.b. demand inventory.c. echelon inventory.d. safety inventory.e. none of the aboveAnswer: cDifficulty: Hard48. A distributor should decide his safety inventory levels based ona. the level of safety inventory carried by all retailers supplied by him.b. the level of safety inventory carried by other distributors.c. the level of safety inventory carried by manufacturers supplying him.d. the level of cycle inventory carried by all retailers supplied by him.e. the level of cycle inventory carried by other distributors.Answer: aDifficulty: Hard49. As retailers decrease the level of safety inventory they carry, the distributor willhave toa. decrease his or her safety inventory.b. increase his or her safety inventory.c. keep his or her safety inventory at the same level.d. increase his or her cycle inventory.e. decrease his or her cycle inventory.Answer: bDifficulty: HardEssay/Problems1. Discuss the role of safety inventory in the supply chain and the trade-offsinvolved.Answer: The primary role of safety inventory is providing product availability forcustomers when demand and supply are uncertain. The trade-off that a supplychain manager must consider when planning safety inventory involve productavailability and inventory holding costs. On one hand, raising the level of safetyinventory increases product availability and thus the margin captured fromcustomer purchases. On the other hand, raising the level of safety inventoryincreases inventory holding costs. This issue is particularly significant inindustries where product life cycles are short and demand is very volatile.Carrying excessive inventory can help counter demand volatility but can reallyhurt if new products come on the market and demand for the product in inventory dries up. The inventory on hand then becomes worthless.In tod ay’s business environment, firms experience great pressure to improveproduct availability while increasing product variety through customization. As aresult, markets have become increasingly heterogeneous and demand forindividual products is very unstable and difficult to forecast. Both the increasedvariety and the increased pressure for availability push firmsto increase the level of safety inventory they hold.At the same time, product life cycles have shrunk. This increases the risk to firms of carrying too much inventory. Thus, a key to the success of any supply chain isto figure out ways to decrease the level of safety inventory carried without hurting the level of product availability.Difficulty: Hard2. Discuss the various measures of product availability.Answer: Product availability reflects a firm’s ability to fill a customer order out ofavailable inventory. A stockout results if a customer order arrives when product is not available. There are several ways to measure product availability. Allavailability measures are defined on average over a given time frame, which can range from hours to a year.Product fill rate (fr) is the fraction of product demand that is satisfied from product in inventory. It is equivalent to the probability that product demand is suppliedfrom available inventory.Order fill rate is the fraction of orders that are filled from available inventory. In amulti-product scenario, an order is filled from inventory only if all products in theorder can be supplied from the available inventory. Order fill rates tend to belower than product fill rates because all products must be in stock for an order to be filled.Cycle service level(CSL) is the fraction of replenishment cycles that end with all the customer demand being met. A replenishment cycle is the interval betweentwo successive replenishment deliveries. The CSL is equal to the probability ofnot having a stockout in a replenishment cycle. Observe that a CSL of 60 percent will typically result in a much higher fill rate.The distinction between product fill rate and order fill rate is not significant in asingle product situation. When a firm is selling multiple products, however, thisdifference may be significant. For example, if most orders include 10 or moredifferent products that are to be shipped, an out-of-stock situation of one product results in the order not being filled from stock. The firm in this case may have apoor order fill rate even though it has good product fill rates. Tracking order fillrates is important when customers place a high value on the entire order beingfilled simultaneously.Difficulty: Moderate3. Describe the two types of ordering policies and the impact each has on safetyinventory.Answer: A replenishment policy consists of decisions regarding when to reorderand how much to reorder. These decisions determine the cycle and safetyinventories along with the fr and the CSL. There are several forms thatreplenishment policies may take. We restrict attention to two instances:1. Continuous review: Inventory is continuously tracked and an order for a lotsize Q is placed when the inventory declines to the reorder point (ROP). The time between orders may fluctuate given variable demand. When using a continuousreview policy, a manager has to account only for the uncertainty of demandduring the lead time (L).2. Periodic review: Inventory status is checked at regular periodic intervals andan order is placed to raise the inventory level to a specified threshold. In thiscase, the time between orders is fixed. The size of each order, however, canfluctuate given variable demand. Periodic review replenishment policies requiremore safety inventory than continuous review policies for the same lead time andlevel of product availability, because the safety inventory has to cover fordemand uncertainty over the lead time and the review interval (L + T). Periodicreview policies are simpler to implement for retailers because they do not require that the retailer have the capability of continuously monitoring inventory. Giventhat higher uncertainty must be accounted for, periodic review policies will requirea higher level of safety inventory.Difficulty: Moderate4. Explain the impact of supplier lead time on safety。
supply-Chain-management(中文)
供应链管理供应链管理(Supply Chain Management ,简称SCM)目录[隐藏]∙ 1 供应链管理的定义与内容∙ 2 供应链管理方法∙ 3 为什么要实施供应链管理∙ 4 供应链管理与优化的方法∙ 5 供应链管理提出的时代背景[1]∙ 6 供应链管理中的关键问题∙7 供应链管理的发展趋势∙8 供应链管理理论的演进[2]∙9 供应链管理的载体[7]∙10 供应链管理的基本要求[7]∙11 供应链管理的方法∙12 供应链管理的步骤∙13 供应链管理面临的挑战∙14 供应链管理的四大支点o14.1 1、以顾客为中心o14.2 2、强调企业的核心竟争力o14.3 3、相互协作的双赢理念o14.4 4、优化信息流程∙15 供应链管理思想∙16 供应链管理的八大管理原理∙17 供应链管理的战略意义[7]∙18 实施供应链管理的对策[7]∙19 SCM在制造业的实施[1]∙20 供应链管理案例分析o20.1 案例一：中国石油电子商务[8]o20.2 案例二：丰田汽车精细流程[8]o20.3 案例三：戴尔公司[9]o20.4 案例四：德州仪器的供应链管理[10]∙21 相关链接∙22 参考文献[编辑]供应链管理的定义与内容供应链管理(Supply Chain Management ,简称SCM)：就是指在满足一定的客户服务水平的条件下，为了使整个供应链系统成本达到最小而把供应商、制造商、仓库、配送中心和渠道商等有效地组织在一起来进行的产品制造、转运、分销及销售的管理方法。
供应链管理包括计划、采购、制造、配送、退货五大基本内容。
计划：这是SCM的策略性部分。
你需要有一个策略来管理所有的资源，以满足客户对你的产品的需求。
好的计划是建立一系列的方法监控供应链，使它能够有效、低成本地为顾客递送高质量和高价值的产品或服务。
采购：选择能为你的产品和服务提供货品和服务的供应商，和供应商建立一套定价、配送和付款流程并创造方法监控和改善管理，并把对供应商提供的货品和服务的管理流程结合起来，包括提货、核实货单、转送货物到你的制造部门并批准对供应商的付款等。
供应链管理课后习题答案
第一章课后习题答案一、判断题SCP:分别指市场结构(Structure )，市场行为(Conduct)，市场绩效(Performance)。
哈佛学派认为. 市场结构(Structure )，市场行为(Conduct)，市场绩效(Performance)之间存在着必然的联系.並建立了SCP分析框架來分析行业与企业的发展情況P5三、简答题1答：分析汽车供应链结构简图：（1）汽车行业全球供应链的形成与发展在激烈的市场竞争中，汽车制造业是一个复杂程度和集成度非常高的行业，汽车制造业需要懂得合作与共享，并且在不同的环节有着不同的侧重点，满足不同客户需求，不断完善汽车产业全球价值链的分工体系，才能在激烈的市场中成为佼佼者。
（2）汽车供应链的利益分配及影响因素“微笑曲线”价值分布汽车供应链中有不同的侧重点，对于整车装配、非关键零部件的生产加工、流通环节等均为低附加值环节；对于产品设计与研发、品牌推广和关键零部件的生产和采购等则划分为高附加值环节，汽车企业应重视“微笑曲线”所带来的价值，针对不同的区域有不同的侧重点，有利于节省成本，提高质量。
特征：多种生产策略组合；典型的生产滚动计划；整车厂的生产计划实施，驱动整个供应链；普遍注重精益的物流运作；物流业务外包成主流；严格的零部件供应商准入机制与供应商分级管理；基于框架协议下的全球化采购；汽车售后供应链体系备受关注。
汽车产业发展新趋势汽车产业发展呈现规模化、集群化发展趋势，产业集群化使产业链纵向延伸发展，同时提高了与相关产业进行横向竞争与合作的效率2、答：分析服装供应链结构简图：先分析服装供应链的工艺流程，再分析服装供应链的类型。
服装供应链有四种主要类型的企业：（1）单纯的生产加工企业（2）自有品牌的“虚拟企业”（3）供、产、销一体化的企业（4）服装贸易公司特征：（1）服装产品的生命周期短(2)服装消费需求变动性大(3)服装消费需求的可预测性低(4)服装购买的冲动性高(5)服装产品被模仿的情况严重P14-15发展趋势：（1）产品个性化需求增大消费能力、消费心理与社会的进步三个因素，共同催生了个性化定制这个基于人自身表达诉求的概念。
Supply Chain Management
Supply Chain ManagementSupply chain management is a critical component of any business, ensuring that products and services reach customers in a timely and cost-effective manner. It involves a complex network of activities, including sourcing raw materials, manufacturing, inventory management, transportation, and distribution. In this response, we will explore the various aspects of supply chain management,including its importance, the challenges, and potential solutions.The Importance of Supply Chain ManagementSupply chain management is essential for businesses to remain competitive in today's global market. It helps companies to optimize their operations, reduce costs, and improve customer satisfaction. By effectively managing the flow of goods and information, businesses can ensure that they meet customer demands while minimizing waste and inefficiencies.One of the key benefits of supply chain management is the ability tostreamline operations. By analyzing data and identifying patterns, businesses can make informed decisions about production, inventory levels, and distribution. This can lead to reduced lead times, lower inventory costs, and improved customer service.Challenges in Supply Chain ManagementDespite its many benefits, supply chain management also presents several challenges. One of the most significant is the complexity of the supply chain itself. With multiple stakeholders, each with their own goals and priorities, coordinating activities can be difficult. This can lead to delays, increased costs, and reduced customer satisfaction.Another challenge is the unpredictability of the market. Changes in consumer demand, economic conditions, and geopolitical events can all impact the supplychain. Businesses must be agile and adaptable to respond to these changes and maintain a competitive edge.Potential Solutions for Supply Chain ManagementTo overcome these challenges, businesses can implement various strategies and technologies. One approach is to adopt a more collaborative mindset, workingclosely with suppliers, manufacturers, and distributors to align their goals and share information. This can help to improve communication, reduce errors, and increase efficiency.Another solution is to invest in technology that can help to automate and optimize supply chain processes. For example, advanced analytics can be used to predict demand and to optimize inventory levels. Blockchain technology can also be used to improve transparency and traceability, helping to ensure the quality and integrity of products.In addition, businesses can focus on building resilience into their supply chains. This can involve diversifying suppliers, investing in contingency planning, and developing strong relationships with key stakeholders. By building a more robust supply chain, businesses can better withstand disruptions and maintaintheir operations during challenging times.The Human Element in Supply Chain ManagementWhile technology and automation play a significant role in supply chain management, the human element is also crucial. People are responsible for making decisions, solving problems, and building relationships with suppliers and customers. By fostering a culture of collaboration, innovation, and continuous improvement, businesses can create a more agile and responsive supply chain.Emotional intelligence is another important aspect of supply chain management. By understanding and managing their own emotions and those of others, supply chain professionals can build stronger relationships, negotiate more effectively, andnavigate complex situations. This can lead to better outcomes for the business and its stakeholders.The Future of Supply Chain ManagementAs technology continues to advance, the future of supply chain management is likely to be increasingly digital and automated. Artificial intelligence, machine learning, and the Internet of Things (IoT) are all poised to transform the way businesses manage their supply chains. These technologies can help to optimize processes, improve decision-making, and enhance visibility across the entiresupply chain.However, it is important to remember that technology is not a panacea. Human expertise, creativity, and emotional intelligence will continue to be essential components of supply chain management. By combining the best of both worlds, businesses can create supply chains that are not only efficient and cost-effective, but also adaptable, resilient, and responsive to the needs of customers and stakeholders.In conclusion, supply chain management is a complex and multifaceteddiscipline that plays a critical role in the success of businesses. By understanding the importance of supply chain management, addressing its challenges, and embracing potential solutions, businesses can create supply chains that are both competitive and sustainable. The future of supply chain management is likely to be shaped by technology, but the human element will remain essential inensuring its success.。
supply chain
If the retailer receives 100 boxes of shirts (and each box contains 24 shirts) it has to fold 2,400 shirts! If the average store employee can fold 60 shirts per hour, this represents 40 hours (or 1 week) of labor. At $15 per hour, the cost to do this is $600. Of course, the consumer 由于供应链具备为企业极大 ultimately pays 降低成本和增加收益的潜能 for this as it is part of the shirt’s cost, however it is an unnecessary cost 。 as the 而成为企业新的竞争领域 supplier can be told to re-fold at 8 inches. The new competitive frontier is across supply chains as they have the potential to significantly reduce costs and increase profitability for companies.
使---最优化 （完善） Furthermore, software for optimization
has been embraced by all of these parties, as it offers mathematical 最佳 modeling solutions to supply chain 的 problems. For example, a software package might provide an optimum delivery route of the products, from supplier to manufacture. In conclusion, the goal is to optimize efficiency through supply chain management.
供应链管理_第三版_Unit11_习题与答案
Chapter 11Managing Uncertainty in the Supply Chain: Safety InventoryTrue/False1. Safety inventory is inventory carried for the purpose of satisfying demand thatexceeds the amount forecasted for a given period.Answer: TrueDifficulty: Moderate2. Raising the level of safety inventory increases product availability and thus themargin captured from customer purchases.Answer: TrueDifficulty: Moderate3. Carrying excessive inventory can help counter demand volatility when newproducts come on the market.Answer: FalseDifficulty: Moderate4. The appropriate level of safety inventory is determined by the uncertainty of bothdemand and supply and the desired level of cycle inventory.Answer: FalseDifficulty: Moderate5. As the uncertainty of supply or demand grows, the required level of safetyinventories increases.Answer: TrueDifficulty: Moderate6. As the desired level of product availability increases, the required level of safetyinventory decreases.Answer: FalseDifficulty: Easy7. Lead time is the gap between when an order is placed and when it is received.Answer: TrueDifficulty: Easy8. The coefficient of variation measures the size of the relative certainty of cycleinventory.Answer: FalseDifficulty: Easy9. Product availability reflects a firm’s ability to fill a customer order out of availableinventory.Answer: TrueDifficulty: Moderate10. Order fill rate is the fraction of product demand that is satisfied from product ininventory.Answer: FalseDifficulty: Moderate11. Product fill rate is the fraction of product demand that is satisfied from product ininventory.Answer: TrueDifficulty: Moderate12. The distinction between product fill rate and order fill rate is significant in a singleproduct situation.Answer: FalseDifficulty: Hard13. Tracking order fill rates is important when customers place a high value on theentire order being filled simultaneously.Answer: TrueDifficulty: Easy14. With continuous review, inventory is continuously tracked and an order for a lotsize Q is placed at regular intervals of time.Answer: FalseDifficulty: Hard15. With periodic review, inventory status is checked at regular intervals and an orderis placed to raise the inventory level to a specified threshold.Answer: TrueDifficulty: Hard16. The expected shortage per replenishment cycle(ESC) is the average units ofdemand that are satisfied from inventory in stock per replenishment cycle.Answer: FalseDifficulty: Hard17. A shortage occurs in a replenishment cycle only if the demand during the leadtime exceeds the ROP.Answer: TrueDifficulty: Moderate18. The required safety inventory grows rapidly with a decrease in the desiredproduct availability.Answer: FalseDifficulty: Easy19. In most supply chains, the key to reducing the underlying forecast uncertainty isto link all forecasts throughout the supply chain to customer demand data.Answer: TrueDifficulty: Moderate20. A reduction in supply can help dramatically reduce safety inventory requiredwithout hurting product availability.Answer: FalseDifficulty: Moderate21. Aggregation reduces the standard deviation of demand only if demand acrossthe regions being aggregated is not perfectly positively correlated.Answer: TrueDifficulty: Moderate22. The lower the coefficient of variation of an item, the greater the reduction insafety inventories as a result of centralization.Answer: FalseDifficulty: Hard23. Manufacturer-driven substitution increases overall profitability for themanufacturer by allowing some aggregation of demand, which reduces theinventory requirements for the same level of availability.Answer: TrueDifficulty: Moderate24. Periodic review policies require more safety inventory than continuous reviewpolicies for the same level of product availability.Answer: TrueDifficulty: Easy25. When using a continuous review policy, a manager has to account for theuncertainty of demand during the lead time and the review interval.Answer: FalseDifficulty: EasyEssay/Problems1. Discuss the role of safety inventory in the supply chain and the trade-offsinvolved.Answer: The primary role of safety inventory is providing product availability for customers when demand and supply are uncertain. The trade-off that a supply chain manager must consider when planning safety inventory involve productavailability and inventory holding costs. On one hand, raising the level of safetyinventory increases product availability and thus the margin captured fromcustomer purchases. On the other hand, raising the level of safety inventoryincreases inventory holding costs. This issue is particularly significant inindustries where product life cycles are short and demand is very volatile.Carrying excessive inventory can help counter demand volatility but can reallyhurt if new products come on the market and demand for the product in inventory dries up. The inventory on hand then becomes worthless.In today’s business environment, firms experience great pressure to improveproduct availability while increasing product variety through customization. As aresult, markets have become increasingly heterogeneous and demand forindividual products is very unstable and difficult to forecast. Both the increasedvariety and the increased pressure for availability push firms to increase the level of safety inventory they hold.At the same time, product life cycles have shrunk. This increases the risk to firms of carrying too much inventory. Thus, a key to the success of any supply chain is to figure out ways to decrease the level of safety inventory carried without hurting the level of product availability.Difficulty: Hard答：主要作用是提供安全库存产品供应顾客时，供给和需求是不确定的。
1.supply chain management供应链管理
carry on:经营，从事 coordinated：协调
练习：
项目管理将工商管理的所有功Байду номын сангаас整合于一 个项目小组以达到协调管理的目的。
cycle time
Text 1 Supply Chain Management
【Para 4】The Goal of Supply Chain Management（供应链管理的目标）
Since World War II, with the development of the operations research and management science, there has been an increasing interest in supply chain planning and management. Working together, supply chain planners/managers and all members of the front, middle and back end of the supply chain may enhance revenue, cost control, and asset utilization as well as customer satisfaction.
Text 1 Supply Chain Management
Optimization promises to improve a company's supply chain performance in a variety of areas： Reducing supply costs Improving product margins Increasing manufacturing throughput Better return on assets
第十一章 供应链的规模经济管理 周转库存
D S C H
= = = =
•
Economies of Scale to Exploit Fixed Costs
• Minimize
– Annual material cost – Annual ordering cost – Annual holding cost
Copyright ©2013 Pearson Education, Inc. publishing as Prentice Hall .
11
Managing Economies of Scale in a Supply Chain: Cycle Inventory
PowerPoint presentation to accompany Chopra and Meindl Supply Chain Management, 5e
Copyright ©2013 Pearson Education, Inc. publishing as Prentice Hall . 11-1 1-1
Copyright ©2013 Pearson Education, Inc. publishing as Prentice Hall . 11-10
E D ( R f + b ´ MRP) + Rb (1 – t ) D+ E D+E
Estimating Cycle Inventory Related Costs in Practice
– Take advantage of economies of scale – Reduce costs in the supply chain
Copyright ©2013 Pearson Education, Inc. publishing as Prentice Hall .
Inventory management in supply chains
*Corresponding author.Tel.:#39-80-5962-763;fax:#39-80-5962-788.E-mail address:pontrandolfo @poliba.it (P.Pontrandolfo).Int.J.Production Economics 78(2002)153}161Inventory management in supply chains:a reinforcement learning approachIlaria Giannoccaro,Pierpaolo Pontrandolfo *Dipa rtimento di Ingegneria Mecca nica e Gestiona le ,Politecnico di Ba ri,Via le Ja pigia 182,70123Ba ri,Ita lyReceived 8August 2000;received in revised form 5September 2000AbstractA major issue in supply chain inventory management is the coordination of inventory policies adopted by di !erent supply chain actors,such as suppliers,manufacturers,distributors,so as to smooth material #ow and minimize costs while responsively meeting customer demand.This paper presents an approach to manage inventory decisions at all stages of the supply chain in an integrated manner.It allows an inventory order policy to be determined,which is aimed at optimizing the performance of the whole supply chain.The approach consists of three techniques:(i)Markov decision processes (MDP)and (ii)an arti "cial intelligent algorithm to solve MDPs,which is based on (iii)simulation modeling.In particular,the inventory problem is modeled as an MDP and a reinforcement learning (RL)algorithm is used to determine a near optimal inventory policy under an average reward criterion.RL is a simulation-based stochastic technique that proves very e $cient particularly when the MDP size is large. 2002Elsevier Science B.V.All rights reserved.Keywords:Supply chain;Inventory management;Markov decision processes;Reinforcement learning1.IntroductionA supply chain (SC)is a network of organiza-tions that are involved in the di !erent processes and activities that produce value in the form of products and services in the hands of the ultimate consumer [1].Such activities are mainly the pro-curement of materials,the transformation of these materials into intermediate and "nished product,and the distribution of "nished products to the end customer.Supply chain management (SCM)is con-cerned with the integrated management of the #ows of goods and information throughout the supply chain,so as to insure that the right goods be de-livered in the right place and quantity at the right time.The SCM literature covers di !erent areas,such as forecasting,procurement,production,distribu-tion,inventory,transportation,and customer ser-vice,under several perspectives,i.e.strategic,tactical,and operational.supply chain inventory management (SCIM),which is the main concern of this paper,is an integrated approach to the plann-ing and control of inventory throughout the entire network of co-operating organizations,from the source of supply to the end user.SCIM is focused on the ultimate customer demand and aims at0925-5273/02/$-see front matter 2002Elsevier Science B.V.All rights reserved.PII:S 0925-5273(00)00156-0improving customer service,increasing product variety,and lowering costs[2].An e!ective management and control of the ma-terial#ow across the boundaries between com-panies and their customers is vital to the success of companies,but is a di$cult task due to the demand ampli"cation e!ect,known as&Forrester e!ect'[3]. The latter depends on factors such as the supply chain structure,the time lags involved in accom-plishing actions(e.g.from the order release to ful-"llment),and the poor decision making concerning information and material#ows.Recent empirical studies[4]demonstrate that inventory manage-ment policies can have a destabilizing e!ect due to the increase in the volatility of demand as it passes up through the chain.For example,Towill[5] claims that the demand ampli"cation experienced across each business interface is about2:1.Lee et al.[6]describe the Bullwhip e!ect occur-ring in supply chains as the considerable increase of the order variability relative to the variability of buyers'demand.They identify the main mecha-nisms that destabilize supply chains,i.e.order batching,price#uctuation,capacity shortfalls that lead to over-ordering and cancellation,and the updating of demand forecast.A tight coordination among inventory policies of the di!erent actors in the supply chain can reduce the ripple e!ect on demand.To this end an appro-priate information infrastructure is necessary that allows all the actors within a SC make decisions synchronized and coherent among each other.Such an infrastructure is referred to as networked inven-tory management information systems(NIMISs) [2].However,the exploitation of the NIMISs requires the adoption of suitable inventory man-agement policies.For instance,Kelle and Milne[7] provide quantitative tools to study the e!ect of an (s,S)policy on the supply chain and show that small frequent orders and the cooperation among the SC partners can reduce demand variability. Towill[5]investigates the impact of di!erent strat-egies,such as JIT,vendor integration,and time-based management,on the reduction of demand ampli"cation.Wikner[8]stresses that the Forres-ter e!ect is lowered through the"ne tuning of existing ordering policies,the reduction of delays, the removal of the distribution stage in the SC,the change of local decision rules,and a better use of the information#ow through the supply chain. Johnes and Riley[9]and Hoekstra and Romme [10]address the optimal positioning of stocks in the chain and suggest the use of strategic stocks to de-couple push from pull operations.Stalk and Hout[11]and Blackburn[12]focus on time com-pression and the integration of operations with both customers and suppliers.Studies on supply chain inventory management generally identify three stages,namely supply,pro-duction,and distribution[13],yet the focus is usu-ally put on the coordination between only two of them[14,13].Coherently,Thomas and Gri$n[15] classify the models for coordinated supply chain management into buyer}vendor coordination, production}distribution coordination,and inven-tory}distribution coordination.To our knowledge,there are only a few ap-proaches that simultaneously analyze inventory decisions at more than two stages under an opera-tional perspective.In this paper,we propose an approach to coordinate inventory management in a supply chain made up of three stages,i.e.supply, production,and distribution.A model based on Markov decision processes(MDPs)and reinforce-ment learning(RL)is proposed to simultaneously design the inventory reorder policies of all the SC stages.After a brief description of MDPs and RL algorithm(Sections2and3),in Section4we de"ne the considered supply chain and the attendant MDP model.Results obtained by the inventory policy determined through the proposed approach are discussed in Section5.2.Markov decision processesA Markov decision process is a sequential deci-sion-making stochastic process characterized by "ve elements[16]:decision epochs,states,actions, transition probabilities,and rewards.An agent(de-cision maker)controls the path of the stochastic process.In fact,at certain points in time in the path, this agent intervenes and takes decisions which a!ect the course of the future path.These points are called decision epochs and the decisions are called actions.At each decision epoch,the system154I.Giannoccaro,P.Pontrandolfo/Int.J.Production Economics78(2002)153}161occupies a decision-making state.This state may be described by a vector.As a result of taking an action in a state,the decision-maker receives a re-ward(which may be positive or negative)and the system goes to the next state with a certain prob-ability which is called the transition probability.A decision rule is a function for selecting an action in each state,while a policy is a collection of such decision rules over the state-space.Implementing a policy generates a sequence of rewards.The MDP problem is to choose a policy to maximize a func-tion of this reward sequence(optimality criterion). Possible choices for these functions include the expected total discounted reward or the long-run average reward.In this article we use the average reward cri-terion.The a v erage reward or gain of a stationary policy ,starting at state i and continuing with policy ,is de"ned as follows:g L(i)"lim, 1NLG ,Rr(X R,>R) ,where r(X R,>R)represents the reward received when using action>R in state X R,>R being the action prescribed by policy in state X.MDPs have been widely applied to inventory control problems[17].For example,they can be used for determining optimal reorder points and quantities.In such a case decision epochs occur periodically,according to an inventory review pol-icy,and the system state is a function of inventory position at the review time.In a given state,actions correspond to the amount of stock to be ordered (with`not ordering a being a possible action).The transition probabilities substantially depend on the ordered quantity,the supply rate,and the demand process until the next decision epoch.A decision rule speci"es the quantity to be ordered at the review time,while a policy consists in a mapping of the replenishment orders onto the possible inven-tory positions.Inventory managers(the decision makers)seek the optimal policy,namely a policy that maximizes a pro"t index(e.g.revenues minus ordering costs and inventory holding costs)over the decision-making horizon.Semi-Markov decision processes(SMDPs)ex-tend MDPs.In fact,di!erently from MDPs where decisions are allowed only at predetermined dis-crete points in time,in SMDPs the decision maker can choose an action any time the system state changes.Moreover,SMDPs model the system evolution in continuous time,and the time spent by the system in a particular state follows a probabil-ity distribution.In SMDPs,the action choice not only determines the joint probability distribution of a subsequent state,but also the time between decision epochs.In general,the system state may change several times between decision epochs,but only the state at the decision epochs is relevant to the decision maker.What happened between two subsequent decision epochs provides no relevant information to the decision maker.Therefore,two processes can be distinguished:(1)the semi-Marko v decision process represents the evolution of the sys-tem state at the decision epochs,and(2)the natural process describes the evolution of states continually throughout time.The two distinct processes coincide at decision epochs.The reward function associated with SMDPs is more complex.When the decision maker chooses action a in state s,"rst he receives a lump sum reward,further he accrues a reward at a rate c(j,s,a)as long as the natural process occupies state j.For i3S,when action a3A G is chosen(for any state i,A G denotes the set of possible actions that can be taken in i),and if the next state is j,let r(i,j,a)represent the reward obtained and t(i,j,a) represent the time spent,during the state transition. Also let i I represent the state visited in the k th epoch and I represent the action taken in that epoch.Then the average reward(gain)of an SMDP starting at state i and continuing with policy can be given asg L(i)"lim, +E[ ,I (r(i I,i I> , I"i "i ))]/N,lim, +E[ ,I (t(i I,i I> , I"i "i ))]/N,.Modeling inventory control problem through SMDPs rather than MDPs presents several ad-vantages.It allows inventory policies to be con-sidered in which review time intervals are not required to be constant as well as makes it possible to have the system accrue rewards(or incur costs) between decision epochs depending on the natural process(inventory holding and pipeline costs are examples of such costs).I.Giannoccaro,P.Pontrandolfo/Int.J.Production Economics78(2002)153}1611553.Reinforcement learningTraditional approaches to solve MDPs and SMDPs,such as value iteration,policy iteration, modi"ed policy iteration,and linear programming, become very di$cult to be applied as system space and action space grow,due to the huge computa-tional e!ort required.Reinforcement learning[18,19]is an arti"cial intelligent technique that has been successfully utilized for solving complex MDPs that model real-istic systems.This technique is a way of teaching agents the optimal control policy[20],which is based on simulation and value iteration,the latter being a traditional method to solve MDPs and SMDPs.The RL model is based on the interaction of two elements,i.e.the learning agent and the en v ironment, and two mechanisms,namely the exploitation and the exploration.The learning agent selects the actions by trial and error(exploration)and based on its knowledge of the environment(exploitation).The environment responds to these actions by an immediate reward, which is called the reinforcement signal,and evolves in a di!erent state.A good action either results in a high immediate rewards directly or leads the system to states where high rewards are obtainable. Using this information(i.e.the reward received),the agent updates its knowledge of the environment and selects the next action.The agent knowledge consists of an R-value for each state-action pair: each R-value is a measure of the goodness of an action in a state.The updating algorithm(which is based on value iteration)ensures that a good envir-onmental response,obtained as a consequence of taking an action in a state,results in increasing the attendant action-value while a poor response re-sults in lowering it.Thus,as the good actions are rewarded and the bad actions are punished over time,some action-values tend to grow and others tend to diminish.When a system visits a state,the learning agent chooses the action with the highest action value. Sometimes the learning agent chooses a random action.This is called exploration,which ensures that all actions are taken in all states.The learning phase ends when a trend appears in all R-values such that it is clear which is the best action in eachstate.The vector that maps every state into theassociated optimal action,represents the learnedoptimal policy.3.1.SMART algorithmSemi-Markov average reward technique(SMART)can be implemented with a simulator ofthe system[20].The environmental responsefor each action is captured from simulating thesystem with di!erent actions in all states.Information about the response is obtainedfrom the immediate rewards received and thetime spent in each transition from one decision-making state to another.The updating of theknowledge base,which has to happen whenthe system moves from one decision-makingstate to a new decision-making state,basicallymeans changing the action value of the actiontaken in the old state(this process is calledlearning).To implement this change apart fromthe response one also needs to use a variablecalled learning rate which is gradually decayed to0as the learning progresses.The probability ofexploration is also similarly decayed to0.Thedecaying scheme may be as follows:a K"M/m where a K is the value of the variable(learning rate or exploration probability)at the m th iteration andM is some predetermined constant.Typically Mis about0.1for exploration probability and0.01for learning rates.Fig.1depicts the steps of theadopted algorithm.4.Supply chain inventory problems andreinforcement learningIn this section it is shown how reinforcementlearning can be used to address supply chaininventory problems.First we describe the con-sidered model of a supply chain,which includesthe main stages identi"ed in the literature(supply,production,and distribution),as well asthe logic of the attendant material and order#ows.Then we code the described model into anSMDP that can be solved through the SMARTalgorithm.156I.Giannoccaro,P.Pontrandolfo/Int.J.Production Economics78(2002)153}161Fig.1.The SMART algorithm.Table1Cost and time variablesCost variablesUnit price P1000 Ordering cost Co G(i"1,2,3)80,80,80 Unit inventory cost(per t.u.)h G(i"1,2,3)10,5,3 Unit pipeline cost(per t.u.)Cp G(i"1,2,3)10,5,3 Unit penalty cost for late delivery(per t.u.)Cb50Time variablesStock review time interval(constant)It10 Transportation time(uniform distribution)T G1}3 DemandMean interval time(exponential distribution)d1When"nal demand cannot be immediately satis-"ed,the system incurs a penalty cost Cb times the waiting time until demand is ful"lled.Although estimating the penalty cost is often di$cult, it proves crucial when responsiveness to market demand is a key performance,which is especially true in time-based competition.4.2.The SMDP modelThe discussed SC inventory management pro-cess,resulting from a given inventory policy,is a stochastic process.This section explains the way in which the inventory process has been mapped into an SMDP and solved through the proposed approach.The SMDP de"nition involves the choice of the reward function to be maximized.This choice is linked to the hypotheses on the cost structure of the inventory model.With this regard,two basic options are available,namely averaging vs.dis-counting the cost.When the time value of money is considered,cost must be discounted rather than averaged.In the considered case,the average reward criterion has been chosen as this is more frequently used in common inventory models(both single stage and multi-echelon).Also,such a cri-terion simpli"es the hypotheses because there is no need to assume a discount factor.Furthermore, averaging is more appropriate when the perfor-mance is analyzed over a time horizon that is theor-etically in"nite.Finally,the reward function has to be associated with the whole supply chain perfor-mance,given that an integrated inventory manage-ment policy has to be determined.Therefore,the a v erage reward or gain over the long run has been utilized,which is de"ned as follows: "(Total Reward)/(Total Time),whereTotal reward"price Tot sell}Tot Cost,Tot sell"products sold at Total Time,Tot Cost"total costs incurred at Total Time.To complete the mapping of the inventory man-agement problem into the SMDP,the decision epochs,the system state variable,and the possible actions in every system state have to be identi"ed.A decision epoch occurs at each stock review time interval,when the actors at all the three stages make decision on inventory.Decision agents are three,as many as the actors in the supply chain. As a decision agent must make decision solely based on the system state,the state variable must provide him with any information that is relevant to an integrated inventory management.In particu-lar,she needs to know the inventory position of the whole supply chain,being inadequate that of her own stage only.Also,an integrated inventory man-agement requires that the three decision makers share a unique reward function,given that the performance index must refer to the supply chain as a whole.Thus,the system state variable is given by the following vector:(IP ,IP ,IP ),which describes the global SC inventory position as the inventory position IP G at every stage i.The inventory position IP G at a given stage de-pends on schedule receipts(SR G),on-hand inven-tory(OH G),and backorders(BO G)as follows:IP G"OH G#SR G!BO G.From the above equation it follows that IP G is not bounded,which would imply an in"nite size of the associated MDP.Therefore,every IP G has been coded so as to let it assume a limited number of values(Table2).At every decision epoch,all decision agents must select the replenishment order quantity for their158I.Giannoccaro,P.Pontrandolfo/Int.J.Production Economics78(2002)153}161Table2Actual and coded inventory positionsActual IP G(!8[!8;!6[[!6;!4[[!4;!2[[!2;0[[0;2[[2;4[[4;6[[6;8[*8 Coded IP G12345678910own stage,i.e.each must take an action that ranges from ordering nothing up to a maximum equal to the stock point capacity plus the current backorder plus the estimated consumption during the trans-portation lead time minus the stock on hand.We have assumed a value of30for such a maximum, which simulation has shown to be as much high to be never reached.The needed capacity can be de-termined by measuring the maximum stock level that is reached at each stage,by simulating the system under the learnt inventory policy.The action space size and the state space size,respectively equal to29,791and1000,yield 29,791,000action values.Their estimated values de"ne the near optimal inventory policy.Even though decision epochs occur at predeter-mined points in time,the considered decision process is an SMDP.In fact,the system state may change as well as cost(rewards)are incurred (accrued)between two subsequent decision epochs. The SMDP has been solved by the SMART algorithm.The learning phase has been simulated by a commercial simulating package ARENA[21]. The learning process,which has required a length of1,500,000time units,has taken about2h on a PC Pentium II450.5.ResultsA near-optimal supply chain inventory policy, which will be referred to as SMART policy,has been determined through the proposed approach. This policy,which can be thought of as an(s,S) policy where both s and S vary with the system state,is relatively simple to be implemented,as it requires the knowledge of just the optimal action to be taken in each of the system states.The e!ectiveness of the SMART policy has been evaluated against a periodic order policy that ad-opts an integrated perspective,as it is based on the minimization of the total SC costs.Such a policy is de"ned by two vectors that specify the stock review time intervals(T ,T ,T )and the target levels(S , S ,S )at each stage.At the stock review timeinterval T G,an order is placed to raise the inventory position up to the target level S G.In particular,the vector(T ,T ,T )has been determined by solving the non-linear programming problem that minimizes the average SC cost,sub-ject to the following relaxed constraints[22]:¹G*¹G\ *0for i"1,2,3.The echelon inventory concept is utilized for com-puting holding costs,so that the average SC cost is given byC "GCo G¹G#12d H G¹Gthe echelon unit holding cost H G at the i th stage being the incremental holding cost of the i th stage with respect to the upstream stage(i!1)th (H G"h G!h G> ).The vector(6,8,8)has been obtained as solution for(T ,T ,T ).The target stock S G has been de"ned equal to the demand during the reorder interval time¹G(¹G d) plus the stock necessary to cover the demand dur-ing the transportation lead time(LT G):S G"(¹G#LT G)d.The safety stock(SS)has been added at the last stage to cope with customer demand uncertainty. Therefore,the order quantity OQ G at every stage is given byOQ "(S #SS)!IP ;O Q "S !IP ;O Q "S !IP .I.Giannoccaro,P.Pontrandolfo/Int.J.Production Economics78(2002)153}161159Table3SMART policy vs.the benchmark policyGain SMART Benchmark (gain) k"1CV"100%)856826 3.63% k"5CV"45%)881852 3.40% k"10(CV"32%)884855 3.39%The performance achieved by the two policies have been measured through simulation runs with a time length of100,000time units.In particular, three demand patterns have been considered,all characterized by Erlang distributions with same demand rates but di!erent variance.The three pat-terns are indeed characterized by three diverse values of the k parameter of the Erlang distribution. As known,the relationships between the k para-meter,the mean ,the variance ,and the coe$c-ient of variation CV of demand are as follows: "k , "k ,CV"1/k .The results are depicted in Table3.The benchmark policy has been adapted to the demand variance by adjusting the safety stock SS. On the contrary,the inventory policy learned for the k"1case has been used for the other demand patterns(k"5and10).This has allowed the ro-bustness of the proposed approach to be veri"ed. It can be observed that the performance in-creases with k for both the SMART and the bench-mark policies,which was expected,given that when k increases demand uncertainty diminishes.Less obvious is that the SMART policy performs better than the benchmark does even for k"5and10, namely when demand is di!erent from that experi-enced during the learning(k"1).In fact,while the learned policy can surely deal with the same demand pattern used during the learning phase,it could show a performance decline for new patterns. Based on the results,we can then conclude that,not only is the SMART policy more e$cient,but is also robust as long as demand undergoes slight changes. The higher e$ciency of the SMART policy is mainly due to the fact that the decision rule,on which basis actions(i.e.replenishment orders) are taken,is more sophisticated.In fact,there is neither a unique reorder point nor a unique reorder quantity.Rather,replenishment orders are placed as complex functions of inventory position:di!er-ently from the benchmark policy,reorder points as well as ordered quantities vary with the global inventory position.Furthermore,the SMART policy considers the stochastic nature of the environment,namely demand and lead time variability,whereas the benchmark policy is determined based on a deter-ministic demand equal to the average and copes with uncertainty through a safety stock.6.ConclusionsIn this paper the SCM problem has been ad-dressed with particular emphasis on inventory management.Supply chain management is widely recognized as a vital source of competitive advant-age,yet SCM techniques,especially in the inven-tory area,are very di$cult to be put into practice, given the high need of information communication and processing involved.To this end many e!orts have been lately devoted to the design of appropri-ate networked inventory management information systems(NIMISs).Despite the e!orts focused on the implementa-tion of NIMISs,relatively less attention has been given to de"ne an appropriate logic for managing inventory,so missing the opportunity of exploiting the potential of such information systems.In par-ticular,integrated approaches to manage inventory decisions at all stages of the supply chain need to be developed.In this paper an approach has been proposed, which addresses this problem.It is based on three techniques,namely Markov decision processes,re-inforcement learning,and simulation.MDPs make it possible to model sequential decision-making problems under uncertainty.RL and simulation allow MDPs to be solved in a wider range of cases than conventional methods(e.g.dynamic and linear programming)do.The approach has been tested on a supply chain model consisting of the supply,manufacturing, and distribution stages.The integrated inventory policy determined through the proposed ap-proach(SMART policy)outperforms a centralized160I.Giannoccaro,P.Pontrandolfo/Int.J.Production Economics78(2002)153}161periodic order policy,which has been used as a benchmark.Also,the SMART policy proves quite robust with respect to slight changes in de-mand.It is expected that the superiority of the SMART policy would be greater for more complex cases. In fact,centralized but simpler policies(such as the POQ based utilized as a benchmark)cannot adapt to complex environments as the SMART policy does.This depends on(i)the ability of simulation modeling of capturing detailed features of the system as well as(ii)the capability of MDPs of describing time dependencies between decisions.Further research should address the issue of hav-ing the supply chain actors actually implementing the optimal policy determined through the pro-posed approach.This is quite a di$cult task,given that the supply chain actors are likely to belong to diverse"rms.Therefore,having them actually share a unique reward function needs a way(e.g.appro-priate incentive mechanisms)to fairly split the higher rewards that the optimal policy would guarantee.References[1]M.Christopher,Logistic and Supply Chain Management,Pitman Publishing,London,1992.[2]M.Verwijmeren,P.Van der Vlist,K.van Donselaar,Networked inventory management information systems: Materializing supply chain management,International Journal of Physical Distribution and Logistics Manage-ment26(6)(1996)16}31.[3]J.W.Forrester,Industrial Dynamics,MIT Press,Cam-bridge,MA,1961.[4]M.P.Baganha,M.Cohen,The stabilizing e!ect of inven-tory in supply chains,Operations Research46(3)(1998) S72}S73.[5]D.Towill,Industrial dynamics modeling of supply chains,Logistics Information Management9(1996)43}56. [6]H.L.Lee,V.Padmanabhan,S.Whang,The bullwhip e!ectin the supply chains,Sloan Management Review38(3) (1997)93}102.[7]P.Kelle,ne,The e!ect of(s,S)ordering policy on thesupply chain,International Journal of Production Econ-omics59(1999)113}122.[8]J.Wikner,D.R.Towill,M.Naim,Smoothing supply chaindynamics,International Journal of Production Economics 22(1991)231}248.[9]T.C.Jones,D.W.Riley,Using inventory for competitiveadvantage through supply chain management,Interna-tional Journal of Physical Distribution and Materials Management17(2)(1987)94}104.[10]S.Hoekstra,J.Romme,Integral Logistics Structures:De-veloping Customer-Oriented Goods Flows,McGraw-Hill, London,1992.[11]G.H.Stalk,T.M.Hout,Competing against Time,HowTime-Based Competition Is Reshaping Global Competi-tion,Free Press,New York,1990.[12]J.D.Blackburn,Time-based Competition:The NextBattleground in American Manufacturing,Irwin,Home-wood,IL,1991.[13]S.Erengu c,A.J.Vakharia,Integrated production/distribu-tion planning in supply chains,European Journal of Op-erational Research115(1999)219}236.[14]C.Forza,Achieving superior operating performance fromintegrated pipeline management:An empirical study,In-ternational Journal of Physical Distribution and Logistics Management26(9)(1996)36}63.[15]D.J.Thomas,P.M.Gri$n,Coordinated supply chainmanagement,European Journal of Operational Research 94(1)(1996)1}15.[16]M.Puterman,Markov Decision Processes:DiscreteStochastic Programming,Wiley Interscience,New York, 1994.[17]E.Porteus,Stochastic inventory theory,in:D.P.Heyman,M.J.Sobel(Eds.),Handbooks of Operations Research, North-Holland,Amsterdam,1990.[18]R.L.Sutton,A.G.Barto,Reinforcement Leaning}AnIntroduction,MIT Press,Cambridge,MA,1998.[19]D.Bertsekas,J.Tsitsiklis,Neuro-Dynamic Programming,Athena Scienti"c,Belmont,MA,1996.[20]T.A.Das,A.Gosavi,S.Mahadevan,N.Marchalleck,Solv-ing semi-Markov decision problems using average reward reinforcement learning,Management Science45(4)(1999) 560}574.[21]W.D.Kelton,R.P.Sadowski,D.A.Sadowsky,Simulationwith Arena,McGraw-Hill,New York,1998.[22]J.A.Muckstadt,R.O.Roundy,1993,Analysis of multistageproduction systems,in:S.C.Graves,A.H.G.Rinnooy Kan, P.H.Zipkin(Eds.),Handbooks in Operations Research and Management Science,Vol.4,North-Holland,Amster-dam,1993.I.Giannoccaro,P.Pontrandolfo/Int.J.Production Economics78(2002)153}161161。
供应链管理的优化：提升运营效率与客户满意度
供应链管理的优化：提升运营效率与客户满意度引言在当今竞争激烈的商业环境中，供应链管理的优化对于企业的成功至关重要。
供应链管理是一个涉及到物流、采购、生产和销售等各个环节的复杂系统，它的高效运作直接关系到企业的运营效率与客户满意度。
本文将从不同的角度探讨供应链管理的优化策略，帮助企业提升运营效率并提升客户满意度。
理解供应链管理什么是供应链管理？供应链管理是指对企业的物流和资源流动过程进行计划、组织、协调和控制的一系列管理活动。
它涵盖了从原材料采购到最终产品销售的整个流程。
供应链管理的核心目标是通过优化流程和资源配置，提高企业的运营效率和降低成本。
供应链管理的重要性一个高效的供应链管理可以为企业带来诸多优势。
首先，它能够缩短产品的交付周期，满足客户的需求，并提高客户满意度。
其次，通过优化库存管理和供应商选择，供应链管理可以帮助企业降低库存成本和采购成本。
此外，供应链管理还可以提高企业的生产效率和资源利用率，从而提高企业的竞争力。
优化供应链管理的策略精确需求预测与库存管理供应链管理的第一步是准确地预测客户需求，并合理安排产品库存。
通过使用先进的预测模型和分析工具，企业可以预测客户需求的变化趋势，从而减少产品的过剩和缺货现象。
此外，采用合理的库存管理方法，如Just-In-Time （ JIT）和Vendor-Managed Inventory（ VMI ），可以帮助企业降低库存水平并提高资金利用效率。
加强供应链协作与沟通供应链管理涉及众多参与者，包括供应商、生产商和分销商等。
为了实现供应链的高效运作，这些参与者之间需要加强合作与沟通。
通过建立稳定的合作关系，并使用适当的信息技术工具，企业可以实现供应链各环节之间的实时数据共享，提高信息流畅度和业务响应速度。
自动化与数字化技术的应用在现代供应链管理中，自动化和数字化技术的应用越来越重要。
企业可以利用物联网、大数据分析和人工智能等技术来实现供应链的自动化和智能化管理。
供应链管理下的库存控制中英文翻译
供应链管理下的库存控制供应链是围绕核心企业，通过对信息流、、资金流的控制，从原材料开始，制成中间以及最终产品，最后由网络把产品送到手中的将、制造商、分销商、、直到最终用户连成一个整体的功能网链结构。
它是一个范围更广的企业结构模式，它包含所有的节点企业。
这条链上的节点企业必须达到同步，协调运行，才有可能使链上的所有企业都能受益。
这也就是理论的核心所在。
控制是影响供应链管理成败的重要因素之一。
它直接关系着供应链的高低和服务质量的好坏。
在供应链管理环境下，库存控制不再仅仅是某个单独企业如何降低库存水平的问题，更需要企业有全局观念，促使供应链整体达到最优。
只有了解供应链管理环境下库存控制的特点及存在的问题才能有针对性地提出解决问题的策略和方法。
一.供应链环境下的库存控制的特点供应链环境下的库存控制不是简单的需求预测和补给，而是通过库存控制获得用户服务与的优化。
供应链环境下的库存控制模式的最高境界是实现供应链的无缝连接，消除供应链企业之间的高库存现象。
供应链管理模式赋予库存控制以下四个方面的新特点：1.供应链管理能够暴露出企业库存控制过程中的潜在问题和危机，加强库存控制程度;2.供应链管理可以有效地降低社会库存量，减少库存控制成本,供应链的形成，要求对组成供应链的各个环节作出优化，建立良好的协作关系，这种关系有利于促进产品快速流通，降低社会库存量，避免库存浪费和资金占用。
3.供应链管理有利于企业从“库存实物控制”向“库存信息控制”的转变，实现信息化库存控制的4.供应链管理确保了企业库存控制的柔性和快速反应能力,供应链管理环境下，企业库存得到了优化，整个供应链中多余，呆滞的库存降到了最低点，面对市场需求的变化，企业可以迅速作出反应，调整产品或是改变策略，有效地规避了企业的经营风险。
二．供应链管理环境下库存控制存在的问题虽然从宏观理论上说，供应链管理环境下的库存控制较之传统管理下的库存控制有诸多优势，但整个供应链毕竟是由多个单一企业所构成，在实际操作中，由于每个企业对供应链管理的理解存在差异，对自身企业获利程度存在担忧，甚至有些企业的独立目标与供应链的总体目标相悖等种种原因，导致在实际运用供应链管理环境下的库存控制理论和方法时，也不免会暴露出许多现实问题。
supplychainmanagement (2)
supplychainmanagement1. IntroductionSupply chain management refers to the coordination and management of all activities involved in the flow of goods and services from suppliers to end customers. It encompasses the processes of procurement, production, inventory management, logistics, and distribution. Effective supply chain management is crucial for businesses to gain a competitive advantage and optimize overall performance.In this document, we will delve into the various aspects of supply chain management, including its definition, key components, benefits, challenges, and best practices. We will also discuss the role of technology in enhancing supply chain management.2. Components of Supply Chain ManagementThe supply chain management process consists of several key components:2.1 ProcurementProcurement involves sourcing and purchasing raw materials, components, and services from suppliers. It is essential to establish strong supplier relationships, negotiate favorable terms, and ensure timely delivery to avoid disruptions in the supply chain.2.2 ProductionProduction refers to the manufacturing or creation of products or services. It involves transforming raw materials into finished goods through various manufacturing processes. Effective production planning and control are necessary to optimize efficiency and minimize waste.2.3 Inventory ManagementInventory management comprises the control and optimization of stock levels. It involves balancing the costs of carrying excess inventory against the risks of stockouts. Accurate demand forecasting, efficient inventory tracking systems, and well-defined replenishment processes are critical for effective inventory management.2.4 LogisticsLogistics involves the transportation and storage of goods throughout the supply chain. It includes activities such as transportation management, warehousing, and order fulfillment. Well-organized logistics ensure timely delivery, minimize transportation costs, and optimize the overall flow of goods.2.5 DistributionDistribution involves getting the finished goods to the end customers. It encompasses activities such as order processing, pick-pack-ship operations, and last-mile delivery. Efficient distribution ensures customer satisfaction by timely delivering products in good condition.3. Benefits of Supply Chain ManagementImplementing effective supply chain management provides several benefits for businesses, including:•Enhanced customer satisfaction by improving order fulfillment and delivery performance.•Reduced costs through optimized inventory levels, efficient transportation, and streamlined processes.•Improved visibility and transparency throughout the supply chain, enabling better risk management and decision-making.•Increased agility and responsiveness to market demand changes and disruptions.•Collaboration and coordination with suppliers and partners to foster innovation and improve overall supply chain performance.4. Challenges in Supply Chain ManagementWhile supply chain management brings numerous benefits, there are also several challenges that organizations must address, including:4.1 Demand VariabilityFluctuations in customer demand can create uncertainties in supply chain operations. It is crucial to have robust demand forecasting models and flexible production and inventory management strategies to handle demand variability effectively.4.2 Supply Chain ComplexityModern supply chains often span across multiple regions, involve various suppliers, and include complex networks. Managing such complexity requires advanced planning and execution capabilities, effective collaboration, and technological solutions.4.3 Risk MitigationSupply chains are susceptible to various risks, including natural disasters, political uncertainties, and supplier disruptions. Developing risk mitigation strategies and contingency plans is critical to minimize the impact of potential disruptions.4.4 Information Sharing and IntegrationEffective supply chain management relies on seamless information sharing and integration among all stakeholders. This includes suppliers, manufacturers, logistics providers, and customers. Integrating different systems and technologies to enable real-time data visibility and collaboration is essential.5. Best Practices for Supply Chain ManagementTo optimize supply chain management, organizations should adopt the following best practices:•Establish strong relationships and partnerships with suppliers based on mutual trust and collaboration.•Invest in advanced technology solutions, such as Enterprise Resource Planning (ERP) systems and Supply Chain Management (SCM) software, toimprove visibility and coordination.•Embrace data analytics and advanced forecasting methods to better predict and meet customer demand.•Implement lean manufacturing and just-in-time (JIT) production principles to eliminate waste and reduce inventory levels.•Continuously evaluate and improve supply chain performance through key performance indicators (KPIs) and regular assessments.•Foster a culture of continuous learning and innovation, encouraging employees to contribute ideas and suggestions for improving supply chainprocesses.6. Role of Technology in Supply Chain ManagementTechnology plays a vital role in enhancing supply chain management processes. Some key technological advancements include:•Internet of Things (IoT) enables real-time tracking and monitoring of inventory, assets, and shipments.•Artificial Intelligence (AI) and Machine Learning (ML) algorithms enhance demand forecasting accuracy and enable predictive maintenance.•Blockchain technology provides enhanced visibility, transparency, and security throughout the supply chain by creating immutable and auditable records.•Robotic Process Automation (RPA) automates manual tasks, reducing errors and improving process efficiency.•Advanced analytics and data visualization tools help identify trends, patterns, and areas requiring improvement.7. ConclusionEfficient supply chain management is essential for organizations to optimize operations, reduce costs, and meet customer expectations. By understanding the key components, benefits, challenges, and best practices associated with supply chain management, businesses can establish robust and resilient supply chains that drive their success in today’s competitive marketplace. Embracing technological advancements further improves supply chain visibility, coordination, and performance.。
生产运营管理名词解释
生产运营管理名词解释生产运营管理（Production and Operations Management，简称POM）是指企业为实现其运营目标而进行的一系列活动和决策。
其主要任务包括规划、组织、协调和控制企业的生产和运营过程，以确保产品或服务按时、高质、低成本地交付给客户。
以下是几个常见的生产运营管理名词的解释：1. 供应链管理（Supply Chain Management）：指企业通过协同各个环节的供应商、制造商、分销商以及最终客户，统一规划和控制整个供应链，以实现成本最小化、服务质量最优化的目标。
2. 质量管理（Quality Management）：指企业在产品或服务的设计、制造和交付过程中，采取一系列的质量控制方法和工具，以确保产品或服务符合客户要求和期望的程度。
3. 提升效率（Productivity Improvement）：指企业通过改进生产和运营过程，提高资源利用率和生产效率，实现同等或更高产出的目标。
4. 库存管理（Inventory Management）：指企业通过科学的库存管理方法和技术，合理控制和优化库存水平，以减少库存成本和风险，并确保能够满足客户需求。
5. 运营策略（Operations Strategy）：指企业在生产和运营活动中制定的战略目标和方法，包括产品开发、工艺设计、生产过程布局、产能规划等方面的决策。
6. 作业管理（Operations Management）：指企业对生产和运营活动进行规划、组织、协调和控制，以实现高效的生产过程和满足客户需求的目标。
7. 供应商管理（Supplier Management）：指企业对供应商进行选择、评估、开发和绩效管理，以确保供应商能够按时提供高质量的原材料和零部件。
8. 项目管理（Project Management）：指企业对特定项目进行的整体规划、组织和控制，以实现项目的目标和交付时间。
9. 运营安全（Operations Safety）：指企业制定和实施的安全管理措施和规范，以确保生产过程中员工和财产安全的目标。
第1章供应链管理概论.期末复习范围-lixin (6)
1
第一节 管理供应链中的规模经济： 周转库存
批量: 供应链的某个阶段在一定时间力要生产或采购的产品数量 周转库存:是平均库存 该（平均）库存的产生是因为生产或采购批量超过顾客需求 影响周转库存管理的因素： 需求特性、供应特性、进货方式、库存仓储的种类以及 订货费用、库存持有成本、缺货损失成本、交易成本等。
13
二、利用固定成本获得规模经济
Example 山姆会员店的购物：固定成本是路上花费的时间 供应链中的订货固定成本：发出订单的管理费用、接收订单和 运输货物的成本。 1. 单一产品的订货批量（经济订货批量） 百买思销售库存的惠普电脑：补给订单的批量Q，每次订货花费 的固定成本S D = 产品的年需求量 S = 每次订货的固定成本 C = 产品的单位成本 h = 按产品成本的百分比计算的每年库存持有成本率
44
2）定期检查的补给策略或定期订货（T，S）策略 在规定的检查间隔时间里检查库存状态，下订单来把 库存水平提高到指定的门槛值 订货时间间隔是固定的，每次订货的批量是波动的 3）不定期目标订货（s，S）策略 它是①和②的综合。 当库存量降到订货点S时，开始订货，订货量的计算 方法与②相同，即： 订货数量s=最高库存限额－现有库存量
36
若ρij = 1，则两个周期的需求完全正相关； 若ρij = −1 ，则两个周期上的需求完全负相关； 若ρij = 0 ，则两个周期上的需求相互独立。 假设L个周期上每个周期的产品需求相互独立，且服从 均值为D、标准差为σD 的正态分布 。 则L期上的总需求服从均值为DL、标准差为σL 的 正态分布。 DL =LD
ch11库存(2)
L
f
S
ss
L
In Excel:
ESC = -ss{1-NORMDIST(ss/L, 0, 1, 1)}
+ L NORMDIST(ss/L, 0, 1, 0)
Example 11.3: - Determine Fill Rate of a given policy
Following Example 11.1-2, given
Supply Chain Management
第十一章 供应链不确定性管理：安全库存 Chapter11 Managing uncertainty in a supply
chain: Safety inventory
Outline:
11.1 安全库存
11.2 怎样确定不确定性和产品的供给水平 11.3 在给定的补给策略下怎样确定安全库存和产品的
ss = ROP-RL=6000-2500*2 =1000 Average Inventory = cycle inventory + ss =Q/2+ss=6000 Average Flow Time = Avg inventory / throughput = 6000/2500 = 2.4 weeks The demand during lead time RL =RL=5000 The standard deviation of the demand in lead time L = 707 CSL = Prob(demand during lead time of L weeks<=ROP)
供给水平 11.4 降低安全库存且不影响产品供给水平的策略
11.1 安全库存
• 什么是安全库存safety inventory?