同步制造与约束理论.ppt

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1、Chapter 18Synchronous Manufacturing&Theory of Constraints同步制造与约束理论The Hockey Stick Phenomenon曲棍球球棒现象The Hockey Stick Phenomenon曲棍球球棒现象The end-of-period rush!Period1234Output($)考前突击考前突击！Synchronous Manufacturing同步制造Which refer to the entire production process working together in harmony to achieve th

2、e goals of the firm.为了实现公司的目标，使整个生产系统协调一致地工作首要特征synchronous manufacturing logic attempts to coordinate all resources so that they work together and are in harmony or are synchronized.In such a synchronous state,emphasis is on total system performance,not on localized performance measures such as lab

3、or or machine utilization.追求企业的全部资源协调、同步运转 追求企业的整体效率，而不是单个生产要素的利用率（如：劳动、设备生产率）。The goal of the firm公司的目标4Goldratt Proclaims哥德瓦特The goal of a firm is to make money.Performance Measurements绩效评价Performance MeasurementFinancial 财务评价Net profitan absolute measurement in dollarsReturn on investmenta relati

4、ve measure based on investmentCash flowa survival measurement 净利润绝对的赚钱数量投资收益率现金流量6Performance MeasurementOperational 运作评价1.Throughputthe rate at which money is generated by the system through sales2.Inventoryall the money that the system has invested in purchasing things it intends to sell3.Operatin

5、g expensesall the money that the system spends to turn inventory into throughput 吞吐量（产销率）库存 运作费用Productivity生产率Does not guarantee profitabilityHas throughput increased?Has inventory decreased?Have operational expenses decreased?不能保证赢利Unbalanced Capacity不平衡的生产能力8Unbalanced Capacity不平衡的生产能力Earlier,we

6、discussed balancing assembly lines.The goal was constant cycle time across all stationsSynchronous manufacturing views constant workstation capacity as a bad decision.早期观点：装配线的生产能力的平衡 同步制造：生产能力的平衡是一种坏观点9The Statistics of Dependent Events独立事件的统计规律Rather than balancing capacities,the flow of product t

7、hrough the system should be balanced Process Time(B)Process Time(A)与其平衡能力，不如平衡物流 Some Capacity Related Terminology术语Capacity生产能力Available time for production可利用的生产时间（工时/台时）Bottleneck瓶颈瓶颈Capacity is less than demand placed on resource瓶颈是指实际生产能力小于生产负荷的一切资源，它是系统内部制约产销率的约束因素，是制造过程中流量最小的地方。实践表明大部分工厂只有为数极

8、少的瓶颈作业。如果没有瓶颈，则意味着存在剩余生产能力，这时应该改变系统暴露出系统瓶颈。Nonbottleneck非瓶颈非瓶颈Capacity is greater than demand placed on resource非瓶颈是指实际生产能力大于生产负荷的一切资源。因此，非瓶颈资源不应该连续不断的工作，因为它的生产能力超过需求量，非瓶颈包含空闲时间。Capacity-constrained resource次瓶颈资源(CCR)Capacity is close to demand placed on resource 次瓶颈资源是指利用率已接近实际生产能力，并且如果作业计划制定的不太好就可

9、能成为瓶颈资源。例如：一般作业车间的CCR可能接受好几个地方的工作任务，如果这些工作任务没有安排好，就会使工作任务之间的间歇时间超过CCR的空闲时间，从而使CCR成为瓶颈。Basic Manufacturing Building Blocks基本制造类型11Bottleneck feeding nonbottleneck瓶颈供给非瓶颈XYMarketCase A12Nonbottleneck feeding bottleneck非瓶颈供给瓶颈YXMarketCase B13Output of Bottleneck and Nonbottleneck assembled into a Produ

10、ct 组装XYAssemblyMarketCase C14Independent Markets独立市场XYMarketMarketCase DMethods of Control控制方法15Components of Production Cycle Time时间构成Setup timethe time that a part spends waiting for a resource to be set up to work on this same partProcess timethe time that the part is being processedQueue timethe

11、 time that a part waits for a resource while the resource is busy with something else 调整时间 加工时间 排队时间16Components of Production Cycle TimeWait timethe time that a part waits not for a resource but for another part so that they can be assembled together 等待时间 空闲时间Idle timethe unused timethe cycle time

12、less the sum of the setup time,processing time,queue time,and wait time Finding the Bottleneck寻找瓶颈的方法寻找瓶颈的方法寻找企业生产系统中的瓶颈有两种方法：一种方法是工序负荷比较表；另一种方法是运用有关工厂的专门知识，考察系统的运行，并与管理人员和工人交谈。17Saving Time节约时间BottleneckNonbottleneckWhat are the consequences of saving time at each process?18Drum,Buffer,Rope鼓、缓冲器、绳子

13、ABCDEF鼓(Drum)缓冲器(InventoryBuffer)Communication绳子(rope)Market市场“鼓（Drum）”“鼓”是一个企业应用TOC的开端，即识别一个企业的“约束”所在。“约束”控制着企业同步生产的节奏“鼓点”。要维持企业内部生产的同步、企业生产和市场需求的同步，存在着一系列的问题。其中一个主要问题就是企业的生产如何能满足市场或顾客的需求而又不产生过多的库存。“缓冲器（Buffer）”“缓冲器”分为“时间缓冲”和“库存缓冲”：“库存缓冲”就是保险在制品，其位置、数量的确定原则同“时间缓冲”。“时间缓冲”则是将所需的物料比计划提前一段时间提交，以防随机波动，以

14、约束资源上的加工时间长度作为计量单位。“绳子（Rope）”“约束”决定着生产线的产出节奏，而在其上游的工序实行拉动式生产，等于用一根看不见的“绳子”把“约束”与这些工序串联起来，有效地使物料依照产品出产计划快速地通过非约束作业，以保证约束资源的需要。所以，“绳子”起的是传递作用，以驱动系统的所有部分按”鼓”的节奏进行生产。在DBR的实施中，“绳子”是由一个涉及原材料投料到各车间的详细的作业计划来实现的。22Inventory Cost MeasurementDollar Days 美元日A measurement of the value of inventory and the time i

15、t stays within an area 一定范围内的库存及其停留时间的一个测量指标Dollar Days=(value of inventory)(number of days within a department)Example23Benefits from Dollar Day Measurement美元日的应用Marketingdiscourages holding large amounts of finished goods inventory Purchasingdiscourages placing large purchase orders that on the surface appear to take advantage of quantity discountsManufacturingdiscourage large work in process and producing earlier than needed 市场营销反对大量成品库存采购反对大量采购制造反对大量在制品，提前完工