16第十六章 准时制与精益生产系统.docx

1、16第十六章 准时制与精益生产系统第十六章 准时制与精益生产系统主要内容Outline 16.1 准时制和精益生产 Just-in-Time and Lean Production 减少浪费(存储+检查+延迟+闲置)+减少偏差+拉动式+短周期+零库存16.2供应商Suppliers JIT伙伴关系的目标Goals of JIT Partnerships减少不必要活动+减少在制品库存+减少在途库存(寄售库存)+淘汰不合格供应商 供应商关注的问题Concerns of Suppliers对多样性的需要+顾客计划差+工程变更多+质量保证要求严+少批量+地理临近16.3 JIT布置JIT Layout

2、 短距离Distance Reduction 增加柔性Increased Flexibility 对员工的影响Impact on Employees交流+沟通+学习 减少空间和库存Reduced Space and Inventory16.4库存Inventory-准时制库存 降低偏差Reduce Variability 减少库存Reduce Inventory 缩小批量Reduce Lot Sizes 降低调整成本Reduce Setup Costs16.5调度Scheduling 平准作业计划Level Schedules 看板Kanban16.6质量Quality高质量+低成本+少库存1

3、6.7员工授权Employee Empowerment 最了解一项工作的人是从事这项工作的人16.8精益生产Lean Production 建立精益组织Building a Lean Organization 5 Ss5S-引进家务管理的结果4S 店=Sale、Spare part、Service、Survey，汽车特许经营模式。+整理/清除Sort/segregate+简化/整顿Simplify/straighten+清洁/打扫Shine/sweep+标准化Standardize+保持/自律Sustain/self-disciplineTwo additional Ss+安全Safety+支

4、持/维护Support/maintenance 七种浪费Ohnos Seven Wastes大野耐一Taiichi Ohno+过量生产Overproduction+排队等待Queues+多余运输Transportation+多余库存Inventory+多余动作Motion+过度加工Over processing+缺陷Defective products16.9服务业的JITJIT In Services 案例 格林动力单车公司Global Company Profile: Green Gear Cycling Bike Friday 是一款装在手提箱里的自行车，单+双人自行车。 生产是按订单生

5、产的；高质量+高度定制+价格实惠+一天 采用大规模定时生产方式进行生产；快速响应订单+快速生产+高效的供应商合作-低库存+工作单元加工+消除设备调整时间 JIT作为一种持续改进的理念，它有助于消除浪费，支持精益组织； 精益组织的10个基本要素 灵活的的资源 成组单元布置 拉动系统 看板 小批量 设备的快速调整 均衡生产 质量的源头控制 全面生产维护 供应商网络 精益生产的好处 降低库存 提高质量 降低成本 减少生产场地的需求 缩短提前期 提高生产率 提高柔性 改善与供应商的关系 简化计划与控制活动 提高能力 更好的使用人力资源 更多的产品种类16.1 准时制和精益生产Just-In-Time

6、and Lean Production 手段-目的 准时制just-in-time:是一种管理理念，是支持精益生产的一种持续消除浪费的问题解决方案。JIT is a philosophy of continuous and forced problem solving that supports lean production 精益生产lean production:通过持续改进的方式在顾客要求的时间为顾客提供需要的产品，非常精确且没有浪费。Lean production supplies the customer with their exact wants when the custome

7、r wants it without waste JIT是一种拉动的生产系统。Key issues are continual improvement and a pull system；许多公司仍采用推动系统；+同步制造 JIT的核心：减少浪费+减少偏差+拉动系统 减少浪费： 任何不能为产品增加价值的东西都是浪费。Waste is anything that does not add value from the customer point of view 库存、检查、延迟、等待、缺陷的产品都是100%浪费Storage, inspection, delay, waiting in que

8、ues, and defective products do not add value and are 100% waste 更快传递速度、减少在制品、提高生产力都可以减少浪费Faster delivery, reduced work-in-process, and faster throughput all reduce waste 强调质量，减少差错Reduced waste reduces room for errors emphasizing quality 将减少库存资产用于更高产的用途Reduced inventory releases assets for other, pro

9、ductive purposes 减少偏差： 要求管理人员尽量减少内外部偏差JIT systems require managers to reduce variability caused by both internal and external factors 偏差variability是指任何与最优流程的差异Variability is any deviation from the optimum process最优流程是一种每次都能按时生产出完善产品的流程。 库存掩盖偏差Inventory hides variability 偏差越少，浪费越少Less variability res

10、ults in less waste 偏差产生的原因零部件+工艺+技术+工人+顾客 员工、机器及供应商不能提供符合标准的零部件Employees, machines, and suppliers produce units that do not conform to standards, are late, or are not the proper quantity 工程图纸或技术说明不精确Engineering drawings or specifications are inaccurate 生产工人试图提前开始工作Production personnel try to produce

11、 before drawings or specifications are complete 顾客需求未知Customer demands are unknown 拉动系统拉动与推动Pull Versus Push Systems JIT-Pull 拉式系统pull system 将物料按需要拉到所需地点的系统 使用信号向上一级工序传递需求信息A pull system uses signals to request production and delivery from upstream stations 上道工序只有在收到信号才开始生产Upstream stations only pr

12、oduce when signaled 拉动概念用于内部生产也用于供应商关系System is used within the immediate production process and with suppliers 小批量物料拉动供应系统，使库存缓冲被取消，暴露问题，促进持续改进By pulling material in small lots, inventory cushions are removed, exposing problems and emphasizing continual improvement 制造周期缩短Manufacturing cycle time is

13、 reduced制造周期由原料投入到产品产出所需的时间； 传统的推式系统 push system总是有上游向相邻的下游工作点发送生产指令，而不考虑下游的能力、时间与资源问题Push systems dump orders on the downstream stations regardless of the need 制造周期manufacturing cycle time是从接收到原料到发送产成品的时间。JIT可以缩短制造周期案例北方电讯公司Northern Telecom采用JIT收到良好效果. 3周-4小时； 由47降24人； 生产问题减少97%。 JIT竞争优势要求+效果JIT an

14、d Competitive Advantage JIT的要求 供应商+布置+库存+调度+预防性维护+高质量生产+员工授权+承诺 供应商Suppliers 减少供应商数量reduced number of vendors 相互支持的供应商关系supportive supplier relationships 及时供应符合质量要求的物料quality deliveries on time 布置 Layout 采用工作单元布置，在每道工序都有检查环节work-cell layouts with testing at each step of the process 成组技术group technol

15、ogy 可移动的、可调整的、柔性的机械movable, changeable, flexible machinery 工作场所整洁有序high level of workplace organization and neatness 减少库存占地reduced space for inventory 物料直接运送到工作区delivery direct to work areas 库存Inventory 小批量small lot sizes 短调整时间low setup times 能装固定数量部件的容器specialized bins for holding set number of par

16、ts 调度Scheduling 没有偏差的执行计划zero deviation from schedules 平准计划level schedules 让供应商了解计划suppliers informed of schedules 看板技术Kanban techniques 预防性维护Preventive Maintenance 有维护计划scheduled 日常维护daily routine 操作者参与维护operator involvement 高质量生产Quality Production 统计过程控制statistical process control 高质量供应商quality by

17、 suppliers 公司内部质量管理quality within firm 员工授权Employee Empowerment 员工授权和交叉培训empowered and cross-trained employees 尽量少的工作分类以保证员工的柔性few job classifications to ensure flexibility of employees 培训支持training support 承诺Commitment 对管理层、员工及供应商的支持support of management, employees, and suppliers JIT 的效果 等待和延迟减少，加速

18、产出，释放资产，赢得订单Queue and delay reduction, speedier throughput, freed assets, and winning orders 质量改进，减少浪费，赢得订单Quality improvement, reduces waste and wins orders 降低成本，增加利润或降低销售价格Cost reduction increases margin or reduces selling price 工作场所偏差降低，减少浪费，赢得订单Variability reductions in the workplace reduces was

19、te and wins orders 返工减少，减少浪费，赢得订单Rework reduction, reduces waste and wins orders 结果 获得竞争优势A competitive advantage -以低成本高质量响应顾客需求Faster response to the customer at lower cost and higher quality16.2供应商Suppliers 持有库存是以一种浪费，JIT伙伴关系在于消除浪费和降低成本JIT partnerships exist when a supplier and purchaser work toge

20、ther to remove waste and drive down costs JIT 伙伴关系的特征 供应商-少数+支持 数量-分享需求预测+小批量 质量-符合要求 发货-及时准确16.2.1 JIT伙伴关系的目标 减少不必要的活动Elimination of unnecessary activities 减少在制品库存Elimination of in-plant inventory 减少在途库存Elimination of in-transit inventory寄售库存consignment inventory 淘汰不合格的供应商Elimination of poor suppli

21、ers16.2.2 JIT中供应商关注-顾客存在的问题Concerns of Suppliers 对多样性渴望Diversification 顾客计划不周全Poor customer scheduling 工程变更Frequent engineering changes 质量保证要求高Quality assurance 批量小Small lot sizes 地理接近Physical proximity16.3 JIT布置JIT Layout JIT布置的目标：减少人和物料的移动JIT objective: Reduce movement of people and material 移动是一种

22、浪费Movement is waste! 布置策略JIT Layout Tactics 为产品族建立工作单元Build work cells for families of products 在小区域内进行多种操作Include a large number operations in a small area 缩短距离Minimize distance 设计尽可能小的库存Design little space for inventory 增进员工间的交流Improve employee communication 实用防差错设备Use poka-yoke (fail safe) device

23、s 使用柔性或可移动设备Build flexible or movable equipment 交叉培训员工以增加他们的柔性Cross-train workers to add flexibility16.3.1 缩短距离Distance Reduction 大批量生产线中单一目的设备已被小的灵活的工作单元取代Large lots and long production lines with single-purpose machinery are being replaced by smaller flexible cells 采用短路径的U型布置促进信息交流Often U-shaped f

24、or shorter paths and improved communication 通常采用成组技术Often using group technology concepts 16.3.2 增加柔性Increased Flexibility 工作单元设计的随着产量和设计的变化可以重新布置Cells designed to be rearranged as volume or designs change 办公室环境和生产设施均可调整Applicable in office environments as well as production settings 产品和流程均可改进Facili

25、tates both product and process improvement16.3.3促进相互交流-对员工的影响 对员工进行交叉培训可以提高柔性和效率Employees are cross trained for flexibility and efficiency 改进信息交流可以促进员工之间反馈重要的生产过程信息Improved communications facilitate the passing on of important information about the process 由于几乎没有库存，在第一时间纠正错误至关重要With little or no inv

26、entory buffer, getting it right the first time is critical16.3.4 减少空间和库存 由于减少了库存，库存应该很小With reduced space, inventory must be in very small lots 由于没有空间存储，物料总是在移动Units are always moving because there is no storage16.4库存JIT Inventory准时制库存是指为保持完善的生产系统正常运行所必需的最小库存JIT Inventory is at the minimum level nec

27、essary to keep operations running JIT 库存策略JIT Inventory Tactics 使用拉式系统移动库存Use a pull system to move inventory 减少批量Reduce lot sizes 与供应商建立准时制运送系统Develop just-in-time delivery systems with suppliers 物料直接送到使用地点Deliver directly to point of use 按计划执行Perform to schedule 缩短调整时间Reduce setup time 使用成组技术Use g

28、roup technology16.4.1 降低偏差 库存掩盖了生产系统中的偏差 偏差：废品+调整时间+发货延迟+质量问题+停工16.4.2 减少库存 减少库存减少浪费Problems are exposed 库存是魔鬼-Shingo says “Inventory is evil”16.4.3 缩小批量-降低库存水平 理想的订单批量为1个单位Ideal situation is to have lot sizes of one pulled from one process to the next 通常不可行Often not feasible 使用经济批量模型分析及确定调整时间Can us

29、e EOQ analysis to calculate desired setup time 需要两种改变Two key changes necessary 改进物料搬运和工作流程Improve material handling 减少调整时间Reduce setup time16.4.4 降低调整成本 降低调整成本将降低总成本 调整成本Setup cost curves (S1, S2) 持有成本Holding cost 总成本由调整订货和持有成本的总和Sum of ordering and holding costs 减少调整时间的六步 第一步：将调整工作分为准备和实际调整工作，在机器/流

30、程运行时尽可能多做准备（节省30分钟）Separate setup into preparation and actual setup, doing as much as possible while the machine/process is operating (save 30 minutes) 第二步：将物料放置紧凑，改善物料搬运（节省20分钟）Move material closer and improve material handling (save 20 minutes) 第三步：改善和标准化加工过程（节省15分钟）Standardize and improve tooling (save 15 minutes) 第四部：采用一键式系统消除调整过程（节省10分钟）Use one-touch system to eliminate adjustments (save 10 minutes) 第五步：培训操作员，标准化工作程序（节省2分钟）Training operators and standardizing work procedures (save 2 minutes) 第六步：重复循环，直到调整时间少于1分钟。Rep