计算机技术现代制造技术外文文献翻译/中英文翻译/外文翻译

编号：                   毕业设计 (论文 )外文翻译  （译文）   学     院：         应用科技学院            专     业：      机械设计及其自动化         学生姓名：                        学     号：                               指导教师单位：                                         姓     名：                           职     称：                         2011 年    6 月 12 日                                        1 页  共  29 页   现代制造技术  简介  国际竞争 的激励 和计算机技术应用 的发展 ，在 1980 年制造企业一直追求两个主要的资助方式：   *自动化，   *集成 化 。  自动化是人类功能的机器替代 ；集成 化是减少或消除实体或组织实体之间的缓冲区。后 面 的制造企业应用的新自动化技术策略是多方面的：   *为了在 知识工作中解放出人力资源 ；  *为 了 避免危险或不愉快的工作 ；  *为了提高产品的均匀性 ；   *为了降低成本和多变性。  该战略的实施已经导致公 司在他们的办公室自动化，工厂和实验室走简单，重复的功能。  集成化 ，当作为一种方法来提高质量 、 成本和客户响应 时 ，要求企业想方设法降低各函数的物理，时间和组织上的障碍。这种缓冲减少已实施的消除浪费，  替代的库存信息，计算机技术的插入，或这些的组合。  在大多数加工工业  - 石油精炼，造纸，例如  - 自动化和集成 化有 了数十年的关键趋势。然而，在离散制造产品  - 电子产品和汽车，例如  - 在这些方向重大进展是在美国最近的现象。  本章定义，探讨，并阐明了技术支持朝着更加自动化和离散制造一体化应用趋势的商品。我们首先对已 经发展的硬件和软件技术 进行 讨论。然后，我们看看六个管理，必须加以解决，以支持这些趋势的挑战。最后，我们看看经济评价新技术的问题。  自动化制造  其 特点，例如，东芝公司，在他们的 OME 工程 设施 中 ，自动化制造，可分为三类：  *工厂自动化  *工程自动化  *规划和控制的自动化。  在这三个领域自动化可以独立发生，但三者之间的协调，因为这是由东芝公司正在推行设施，下面讨论 计算机集成 制造驱动器的机会。  工厂自动化  尽管软件也起到了关键作用， 但 工厂自动化 是通过 用于生产中 的 技术硬件 来典型地描述的 ：机器人，数控（ NC）机床，自动 化物料处理系统 ， 越来越多，这些技术被 广泛应用 ，整合为制造单元或柔性制造系统（ FMS）知名的系统。                                       2 页  共  29 页   机器人 这个 术语涉及到一个 自动化 的 设备，通常可编程 的 ，可用搬运材料 到工作台上 （取放）或组装 部件 成一个较大的设备。机器人也可以用来代替直接使用工具或设备的人 力 劳动，例如，通过一个喷漆机器人，焊接机器人，这两个职位的焊工 、 焊接和接缝。 在 复杂 的事物上 机器人 能显著地改变 ，从简单的单轴可编程控制器，到 用 微处理器控制和实时闭环反馈和调整机器 的 复杂的多轴 机器 。   一个数字控制（数控）机床是一台机器工具， 它 可以 通过 一个指导机器 操作的 计算机程序 来运转 ，一个独立的数控机床需要有工件，工具和 NC 程序加载和卸载操作员。然而，一旦数控机床 在 工件上运行一个程序，它需要 的操作明显 低于 手动 操作 机器所需的操作 。   一个 CNC 机床通常有一个小型计算机奉献于它，以便程序可以开发并存储在本地。此外，一些 CNC 机床 有自动装载零件和换刀。 CNC 机床 通常有实时，在线 程序 开发 的 能力，使 操作 可以迅速实施工程变更。  一个 DNC（分布式数控）系统 包含许多 CNC 机床由 一个 很 大的 可以 下载程序到分布式数控机床 的 计算机系统连接起来，这种制度为 用 生产计划和调度零件加工的最终整 合是 必要的。  自动检 测的 工作，也可实现，例如，视觉系统和压力敏感的传感器。检 测 工作往往是乏味和容易出错，尤其是在大批量制造设置，因此 对于 自动化 ， 它是一个很好的候选人。然而，自动检 测 （尤其是诊断能力）往往是十分困难和昂贵。这种情况，在自动化检测系统的发展是 很 昂贵，但人类的检查是容易出错的，体现了自动化制造系统，具有很高的可靠性值：在这种系统中，检验和测试策略可开发高可靠性功能，有可能大大减少了制造和测试的总成本。  自动化物料处理系统 移动工件工作中心 ,存储单元和航运点 ,这些系统可能包括自主导引车，输送系统，或导 轨系统。通过连接在生产系统中 的分离点 ，自动化物料处理系统集成服务功能，减少在生产 过程 中 不同点之间的时间延迟 。 这些系统 促使程序 布局设计来 清晰地 描述，每个工件的路 径 ，往往使小批量运输工件 更 经济，它 供予 减少等候时间的潜力。  柔性制造系统（ FMS）是 这样 一个系统，自动化工作站与 一个 物料输送系统连接 来 提供了 一个 比是在一个高度自动化 、非柔性、 传输线制造的零部件范围更广 的 多 级 的自动化制造 的 能力。 这些系统提供灵活性， 是 因为执行的操作在每个工作站和工作站之间可以通过软件控制不同部分的路由。  该柔性制造系统技术的承诺是提供了弹 性接近 的 能力， 在接近的设备可以用传输线取得的 在工作间 利用率。实际上，柔性制造系统是一种 在 这两个极端中间 的 技术，但良好的管理可以帮助推动双方边界同时进行。  自动化工厂可以显着差异就其战略目的和影响。两个例子，松下，通用电气，可能是有益的。                                       3 页  共  29 页   在大阪，日本，松下电器产业公司拥有生产 磁带 录像机 的设备 。这一行动的心脏功能，有 100 多名工作 站的 高度自动化的机器人装配生产线。除了一 些 故障排除 操作 和过程改进工程师 外 ，这条线可以运行，用很少的人力干预 ， 接近每天 24 小时， 生产 任何型号的 200 录像机 的 组合 ， 截至 1988 年 8 月  。 该设施没有得到充分利用 ；松下准备增加产量，每月运行的设施的时间更多，随着需求的实现。  在这种情况下，生产更多 的 边际成本非常低 ，为 录像机行业准入 ， 松下有效地创建了一个障碍，使进入者很难在价格上竞争。   第二个例子是通用电气公司飞机发动机集团三厂，于琳，马萨诸塞州。这完全自动化的工厂机器的小套零件由飞机发动机集团的装配厂使用。相反，松下 电器 工厂，它负责在录像机产品市场的战略优势，战略优势由 GE 工厂提供的似乎解决其劳动力市场 ，三厂的投资现在 是 沉没 ， 最终，它将 以 一个小 队高效率地日夜不停的 运行。   由于体积 被增加 ， 美 国 通用电气公司有能力利用三厂的 生产力、 成本结构 和 其工会的 劳动力 促使 目前 制造的许多零件 ， 这些零件 最终可能被转移到三厂地区。因此，工厂自动化可以解决从产品市场的考虑 到 劳动市场的担忧 的 多种类型的战略需要。  自动化工程  从最初的概念分析 到最后的 处理计划， 高于 和支持制造业正变得日益自动化 的 工程功能。在许多方面，工程自动化 与 工厂自动化是非常相似 的 ，这两种现象可以大大提高劳动生产率，同时提高了其余员工 的 工作知识比例。然而，对于许多公司来说，经济回报结构和两种技术的理由程序可以完全不同。  自动化和工厂自动化工程之间的差异源 于对技术的两种类型的规模经济差异。在许多情况下，工程自动化的最低有效规模是相当低的。在工程工作站的投资往往是合理与否是网络化，到更大的系统集成。提高工程师的生产率就足够了。   对于工厂自动化的理由， 相反的意见是更频繁的案件 。所谓 “自动化孤岛 ”已经到了意味着在工厂自动化的小投资，其本身的投资提供了一个可怜的回报。许多公司认为，工厂自动化投资必须在质量，交货时间 前 充分结合和 广泛的 在操作 中 普遍，灵活性显现出来。  计算机辅助设计有时被用来作为电脑辅助绘图，电脑辅助工程分析，计算机辅助工艺规划的 涵盖性术语 。这些技术可 用于自动化的工程设计工作带出 来的 大量 苦差事 ，让工程师可以 花他们更多的 时间和精力专注于具有创造性和评估可能 性 更广 的 设计思路。在不久的将来机器 将 不会设计产品。设计功能仍然几乎完全在人类有关的领域。  计算机辅助工程允许用户采取必要的工程分析，如有限元分析，提出设计，同时他们在 绘图板 阶段。这种能力可以显着降低在产品开发周期的需要费时原型和测试。  计算机辅助工艺规划有助于自动产品已被设计的产品，发展 程序 计划的制造工程师的 自动化 工作 ，一旦产品被设计 。  规划和控制自动化                                       4 页  共  29 页   计划和控制的自动化是最密切相关的物料需求计划（ MRP）。古典 的 MRP 开发 生产计划和时间表是通过 利用产品的物料清单和生产前置时间 来 爆炸的客户订单和需求预测当前和预计的，库存水平拘捕和日程安排。  MRP 的系统（第二代 MRP）是制造资源计划系统，建立在基本 MRP 的逻辑，但也包括车间控制模块，资源需求计划，库存分析，预测，采购，订单处理，成本会计，并在不同程度详细容量规划。  在规划和控制的自动化投资的经济因素更为相似， 比如 投资在工厂自动化 比在 工程自动化 是很相似的 。由一个投资 在 MRP II 系统的回报只能通过分析整个生产运作加以估计，也 就 是工厂自动化的情况 ， 该技术的 综 合功能提供了部分的好处 。  集成在制造 业  在制造业领域的四个重要的运动是推动 广泛 制造一体化的实现：   *准时 制 生产（ JIT） ；  *可制造性设计（ DFM） ；  *质量功能展开（ QFD） ；  *计算机集成制造（ CIM）。  其中， CIM 是唯一一个直接关系到新计算机的技术。准时生产，质量功能展开，和可制造性设计 ，这是组织管理方法，不是天生的 计算机 化 和 不依赖任何新技术的发展。我们将在这里简要地看着他们，因为他们是重要的变化， 这些变化是 许多制造业的组织承诺，因为他们 集成 的目标是非常一致的。  准时 制 生产（ JIT）  准时生产 体 现了追求精简或连续流为离散制造产品生产 的 理念。核心理念是降低在整个生产系统的制造安装时间 、 可变性 、 库存缓冲和交货时间，从供应商到客户，以实现产品的高品质，快速，可靠的政绩观 和 低成本。  在一个工厂工作 站之间的工作时间和库存缓冲区 的 减少，以及客户与供应商 之间 ，创建 了 一个更加一体化的生产体系 。 人们在每个工作中心研制出一种更好的需要和他们的前辈和接班人的问题意识 。这种意识，有合作的工作文化相结合，可以帮助显着提高质量和 减少 变异。  技术投资也就是机器和 计算机 ， 它 不需要 JIT 的实施。相反， JIT 是一种管理技术，这种 技术 主要依赖于持续不断追求生产经营逐步改善。如果没有重大的资本投资 ， JIT通过 CIM 完成 一些 相同的整合目标。只是因为它是难以量化成本和中 在 工厂自动化 的投资收益，也难以量化成本和 “软 ”技术作为 JIT 的好处。最近的一些模型试图做这样的量化，但该工作 方法 还没有得到广泛应用。   可制造性设计（ DFM）  这种方法有时被称为并行设计或同步工程。  DFM 是相关的追求设计工程师 、 工艺工程师 和 制造人员 之间更紧密 的沟通和合作 的 一 组 概念集。在许多工程组织，传统产品开发的 实践在 产品设计师完成其工作之前，流程设计人员可以开始他们的 设 计， 以这样                                     5 页  共  29 页   的方式 开 发 产品 将不可避免地需要工程师为制造 产品做 重大 的 工程 变 更 ， 努力寻找一种方法来 降低 度产品成本。  质量 功能展开（ OFD）  密切相关的可制造性设计是质量功能展开（ QFD）的 概念 ， 它 需要增加产品设计师 、营销人员 和 最终用户 之间的交流 。在许多组织中，一旦最初的产品概念 被 开发， 在没有营销人员和工程设计人员之间显着的交互作用 下 将长期通过。因此，作为设计师面临无数的技术决策和权衡，他们 将在 很少的营销或客户 的投入中作出 选择。这种做法在产品引进中 往往导致长期拖延，因为重新设计工作是 非常 必要 的， 一旦营销人看到原型。 质量功能展开正式确定在整个产品开发周期之间的互动营销和工程组，保证决策的设计与所有的技术和市场作出充分 的 权衡考虑。  两者合计， 设计的 可制造与质量功能展开 促进了 工程 、市场 营销 和生产的 一体化，降低 了 总产品开发 的 周期，提高了产品设计的质量，为双方的生产组织和买 该 产品 的顾客所感知 。  就像及时生产 ，可制造性设计与质量功能展开 在本质上 不是 主要 技术 ， 然而，如电计算机 辅助设计技术常常可以用来作为工具 来 促进工程 /制造 /销售一体化。从某种意义上说，这种用法可以 被作为计算机集成 制造 来 实施这些政策的选择。  计算机集成 制造（ CIM）   计算机集成制造是指利用计算机技术 将制造一个产品相关的所有功能 联系在一起 。因此， 计算机集成制造既 是信息系统 又的 制造控制系统。由于它的意图是如此的包罗万象，甚至以一种有意义的方式描述 CIM 都 是很困难的。  我们简述一个相对简单的概念模型， 这概念模型 涵盖了主要的信息需求，并在制造企业 中 流动。该模型由两个系统 单元 类型 组成 ：  *部门的供应和 /或使用的信息 ；  *流程改造，合并，或以某种方式处理信息。  模型中的九个部门为：  1、 生产  2、 采购  3、 销售 /市场营销  4、 工业 与制造工 程  5、 产品设计工程  6、 物料管理和生产 计划  7、管理员 /金融 /会计  8、 工厂和企业管理  9、 质量保证。   *流程改造，合并，或以某种方式处理信息。                                       6 页  共  29 页   1、 成本分析  2、 库存分析  3、 产品线分析  4、 质量分析  5、 劳动力分析  6、 主计划  7、 物料需求计划（ MRP）  8、 机器及设备投资  9、 工艺设计和布局。   为了完成一个特定的制造系统模型的规范，必须 在 上面列出 的部门和 信息处理 之间记录 信息流。 这样的信息流图可以 作为 CIM 的设计概念蓝图，可以 在 可视化的范围和 CIM信息系统的功能 给予帮助 。   设计 并实现一个把 所有信息供应商 、 处理器 和 用户连接在一起 的 计算机 系统是一个漫长，艰难和昂贵的任务。这 样的一个系统必须满足 不同的用户群体的需求， 并且 必须有 不同 的 品种   软件和硬件子系统   经济效益受益于 这样一个系统， 该系统 来自更快 更可靠的通信 ， 里面的 组织内部员工之间以及产品质量和交货时间方面产生的改善更可靠的通信来经济效益。   因为许多 CIM 系统 所带来的好处要么是 无形的 要么是 非常难以量化 的 ， 因此 决定 去追求 CIM 方案 的 必须基于一个长期的 、 战略性的承诺 来 提高制造能力。 描绘 许多美国制造业 关注 的决策过程 的 传统回报投资 的 评估程序将不足以促使大量资金和 需要 时间积极 去 追求 CIM。尽管费 用较高 和 CIM 实施的不确定性， 但 大多数美国大型制造企业 还是投资一些资源 来 探索利用计算机信息 系统 整合其组织 中 各种功能的可行性。   技术采用的影响 ：灵活性和资本密集   如上所述，在工厂自动化和 CIM 投资 中，公司 朝着更加自动化和一体化 的 方向 发展 。为了充分评估这些投资机会，并权衡潜在 违反支付 的 费用 ，我们必须考虑 到这技术的两个影响：   （ 1） 生产经营的灵活性，  （ 2）经营的 密集资本。  在这一节， 在讨论新的制造技术所创造的六个机遇之前 我们 先 简要 的 来看看这两种效应 ：  制造业的灵活性  - 灵活地改变产品结构，改变生产比率， 并通过缩短制造系统内的周转时间 和 自动为不同的产品 进行 设置和更换 来 推出新产品。在过去的十年 ， 制造灵活性的重要性 对 企业 的 竞争力已 很 明显， 因为 经济和技术变革的速度已经加快，许多消费者和工业市场 已经 日益国际化。                                       7 页  共  29 页   由于这种竞争加剧的结果， 当 每家公司 都 要努力 地去 跟上 大群体工业 对手的新产品时， 产品生命周期缩短 了。  为了生存，公司必须迅速作出反应和灵活 去对 竞争 的风险 。因此，企业必须特别 关注 新 制造 技术的灵活性组成部分 的 评估。  增加资本 的 密集是直接从大规模地用机器代替人的自动化。一个 改革 对资本密集的 成本结构有两个重要的 影响。  首先， 来自 低固定投资和高位可变成本 的 制造成本结构的变化， 它 具有很高的 资产固定投资 和 低可变成本。这一变化将显 著地 影响一个公司的挑战竞争能力，因为低可变成本让公司维持甚至面对激烈的价格战的盈利能力 很 短 暂 。  其次，自动调整在这两个 职业 水平和工作责任所带来的变化需要大量的组织 ， 这种挑战所带来的改变在下面讨论。  新的 制造 技术制造 所 创制 的 六项挑战  1. 计算机集成制造系统 的 开发 和设计  由于其雄心勃勃的一体化目标，计算机集成制造系统将是巨大的，复杂的信息系统。理想的情况下，设计过程中应先从 CIM 使命阐述 的 一系列具体目标 和任务的声明之后 开始 。这种自上而下的设计方法，确保了硬件和软件组件 已被 设计成一个有凝聚力的 系统 。  此外，由 自从 CIM 集成的中央数据库加一个分布式数据库组成 的创立 ，数据库设计是 至关重要的 。 并且 ， 自从 组织中的许多人将 要 负责 录 入到系统中的数据，他们必须了解它们 在 整个系统的功能互动。用户的输入必须考虑在设计阶段 和 检查数据库的准确性和完整性 的 系统必须被包括在内。  在系统设计阶段必须考虑硬件和软件的标准化。在许多公司，计算机和数据库 功 能都来自 不同的 供应商， 这些供应商的 产品不是特别兼容。要么重新装备或开发这些计算机系统连 接在一起， 这样 需要大量的资源。  显然，设计一个被确认为组织内外 都 成功 的系统 ，是一项艰巨的挑战。 这样的系统是 很少 的 ，如果 需要 的话，公司 也要按 任务的日期 去 充分 地完成这任务 。   2. 人力资源管理系统  如上所述，重大的调整是需 要合并 新工厂自动化和计算机集成制造技术的实施的组织。如果新技术不是在一个新建的网站安装，那么裁员往往是 这 变化的 一种 后果。有效的减少其余员工可能不可避免地认为这是谁的企业，而不是退却迹象振兴裁员士气问题。  此外，人力资源问题不 是 仅限于 为了 简单地裁减一定数量的人，然后就 向前用 其余团体 。 计算机集成制造 和 自动化技术放在要求能力显着提高的组织 ， 再培训和持续教育必须是企业的希望与这些技术的竞争规则，公司必须经历一个文化转型。  再培训和持续教育的要求至少 是 在工厂车间 做这些 新 技术工作管理人员和工程师。设计 自动化工厂 、 管理自动化工厂 和 自动化工厂设计的产品 与传统的劳动密集工厂相比                                     8 页  共  29 页   它更 都要知识 和技能 的补充 。 高级管理人员必须评估 计算机集成制造 技术以及与他们工作的人， 这 技术也可大大受益于有关的教育。  3. 产品开发系统  工厂自动化和计算机集成制造使产品设计师的工作更加困难。人类 开发的 生产系统比 自动化制造系 统更 适 用， 当设计师正在 为一个手工 建立 产品 设置 要求 时 ， 它 们可以 提供一些模糊的 规格， 它们 知道人类可以容纳组装加工或装配意外所发生的问题，或者至少可以发现问题并 传达这些问题给 设计师重新设计。  在自动设置 中 ，设计人员可以不依赖于制造系统 就 可以轻松地发现和恢复设计 中的错误 ，有严格限制水平的智能和适应性也可以设计成自动化制造系统 ,，因此产品设计必须有非常熟悉生产系统或 与这些有过 亲密交流 的人来做 。发展中国家在该组织的设计能力是 的一定的困难， 但实现世界一流的制造系统却是必要的一步。  4. 管理动态过程 的 改进  在大多数运行良好，劳动力密集的制造系统，由 一支充满活力的员工队伍，不断努力，以发现更好的方法执行其工作 来 不断改进的结果。在一个高度自动化的工厂，有几个工人 去 观察，测试，实验， 考虑和 了解系统以及如何使它更好。因此，一些观察家声称，工厂自动化将意味着学习曲线的末端 是 作为制造业竞争力的重要因素。这种说法 长时间的 违背了工业生产力的进步 ， 一批根本 的技术之后创新一系列 的 有利于不断改进完善新技术。 评估 这一主题 的 大多数学生认为，此种 是 为尽可能多的总生产率的增长，做根本性创新 而 渐进累积的。从本质上讲，任何激进的创新可能会被认为是第一个通过创新， 这一创新 需要更多的创新 ，才达到其最大潜力。  假 定，工厂自动化和 CIM 将扭转为时过早 和 有可能误导管理人员和这些技术的实施者的 这一历史性模式。由于这些技术新 的援助 如此复杂，不能指望所有相关捕捉 的 知识都 在系统设计阶段 里 。如果一个企业承担，一旦 在适当的位置 ，这项技术将不会受到非常多的改善， 它 将评估，设计和管理体系更加不同于如果假定 大多 好处可以通过更多地了解该系统一旦到位如何最好 的 使用和改进。有人可能会希望能观察到自我实现的预言在这方面 ， 即使一个自动化的工厂已经 有一些人 （潜在的创新者）， 投资 在 将能 确保那些目前培训以发现 、 捕捉并尽可能地适用 新知识的人 的 这一技术的公司是明智 的 。事实上，不断发现和利用改进的机会可能是对企业完全避免无人工厂的主要原因。   5.采购技术  在 评估一个 特殊的 技术方案 之前 ，该方案必须合理地明确界定。一个企业需要选择设备和软件供应商，并决定设计 、 生产 、 安装和将与内部工作人员执行 的集成技术的数量 。许多观察家认为，作为 企业 尽可能多的 做 技术开发，以尽量减少对企业的工艺技术信息的泄漏，并保证 一 间公司的新技术和现有的战略 、 人员和资本资产做适当的配合。  对于外部获取 的 技术， 在它们 进行评估 之前， 技术 的 方案必须产生。在制定这些方案 时 ，公司必 须考虑其目前的资产，环境，市场地位，以及作为其竞争对手。设备厂商                                     9 页  共  29 页   必须纳入决策过程 ， 供应商和技术评估标准必须在组织内发展和利用。   6.系统控制和性能评价  一旦技术的投资选择已经实施， 管理者 通常要跟踪该投资的有效性。 衡量制造业 的性能的 传统方法的缺点是广泛的认可。这些方法 的大多数 可以被操纵，以使目前的结果看未来业绩的潜在支出好。 当管理者 仅 花费 在 他们的职业生涯中的一个设施或位置 的 一小部分 时 ，他们往往有动力 去 进行这种操作。此外，在许多环境中，为设施适当的性能标准要求信息的一个或多个竞争对手的设施，上及时，准确的数据 可能不可用。  越来越多的企业正在使用 制造性能的 多维措施。而不是仅仅根据统计汇总盈利能力，质量，交货期，质量成本，交货性能和全要素生产率的措施正在利用评价业绩。尽管这种趋势，企业可以受益于更多的研究，例如，为生产力和学习率的标准 设置一个高度自动化 和 集成 的 环境。  采用新技术 的 经济评估  对于购买 硬件，软件和服务 ， 采用该技术 的 成本是最明显和最容易提前估计前期资本 的 支出。大多数模型只考虑这些费用。但是 下面这些也很重要：（ 1）被 裁 的 员 工 的技能将不会在新系统中使用 所需的费用 ， （ 2）新技术引起的操作设备引起的设备损坏的 费用 （ 3）人力资源发展所需的设计，建造，管理，维护和操作新系统的成本。  投资在工厂自动化和计算机集成制造 是 流程战术和战略的好处。这些利益涉及到一家 公司的成本结构变化，增加 了 工艺重复性和一致性，降低 了 库存，提高 了 灵活性，并缩短流程和通讯线路。  关于投资 在 CIM 的 成本结构和工厂自动化往往代表了大量的前期成本， 这成本 导致了每 个 单位产出的可变成本减少。 这个 主要 是人力劳动 取代机器 的 结果。  当企业之间 的竞争非常 高时，降低 可变成本 可以 提供 显著的 竞争优势，此外，降低可变成本，有时会导致企业削减价格，潜在地增加市场份额和收入 。  CIM 和工厂自动化给予 的 产品 的 重复性 和一致性所引出的优点的增加 也有 着 显 著 提的 竞争力。减少 加工 变异 、 减少废料和 重修定 成本，可变成本储蓄的来源，可以作为通过自动化减少 普通 劳动 力的 成本。此外，提高了产品的一致性， 可以 显 著地 提供产品市场销售 量的 增长。  改进 程序 控制 的二次 影响包括提高 在一个运行良好的系统顺利工作的员工 士气（ 很少 缺勤和离职）  自动化和集成投资 的财产的 库存减少可以来自几个方面 ， 首先，工厂自动化可以减少某些类型的操作设置时间，减少 了 周期库存的需要。 其次 ，降低 程序 变异性可 心 降低性 在 整个 制造 系统 中的 不确定 性 ，减少了安全库存的需要。第三，工厂 集成 可以缩短生产周期，减少了 在制造过程中 通过系统 的 库存 流 。  柔性制造 是 CIM 和工厂自动化提供的另一个重要的战略优势。快速转换工具和设备使公司能够迅速改变产品结构，以响应变化的市场需求。此外，数控编程及 计算机 工艺                                     10 页  共  29 页   设计缩短产品上市时间 和缩短企业 推出 大量 新产品的 时间 。全自动化制造系统提供批量柔 性。前面提到的松下录像机 企业的 高度自动化可以改变其相对较低的产出率 和 通过增加或减少每月运行费用的小时数 来 调整 成本 。因为 该企业的直接劳动力 是相当小，产量下降不会导致戏剧性的开工不足 和 不需要增加 主要雇用和培训工作。  最后，在工作地点交货时间 的 缩短将降低车站之间的工作流程时间，从而减少了制品 在 系统 中 的需要。随着库存和交货时间的减少，企业可能增加快速交货 的利润费用 或可能通过提供更好的服务和保持价格不变 来 增加市场占有率。  概要和结论  增加全球竞争和环境的波动性 要求 企业 能 迅速适应，否则将面临灭绝的可能性。投资于自动化和集成，包括 硬件，比如 自动机和柔性制造系统， 软件，如 计算机集成制造系统 和 如 及时生产、 可制造性设计 和 可以帮助公司实现和保持竞争力的 管理方法。  当然，总是 以 最短的资产供应 的是 管理远见和领导才能。制 造业 战略 创新必须 优 先于技术投资决策，因为良好的技术很少保存不善 的 管理。因此，企业必须补充其有关的信息和对他们的业务挑战和机遇的见解技术 进行 选择 的 学习。  查尔斯任教于麻省理工学院斯隆管理学院 的 经营管理和生产战略。他拥有博士和硕士学位，斯坦福大学的学士学位和杜克大学的学位。他曾撰写了 许多 关于生产问题，包括质量改进的经济性 和 以柔性制造系统的投资模式的 文章。他 经历 的 工业咨询，执行教学和研究项目包括：数字设备工作公司，柯达，通用电气， IBM 和摩托罗拉。   注射成型塑料制品 设计和制造的知识库系统  摘要  本文介绍了一个 重 要塑模 知识库系统的制定和实施。这 知识库 ，名为启迪，是基于网络 技术 建立的 ，因为它的普遍性，易用性，传播 方便性 ，它的超文本，导航和搜索功能，以及支持通过互动 的（ Java， JavaScript，和 CGI）和多媒体（文本，图形，视频和音频）。 按照设计，内容和启示工具可以查看和 共享 在此 过程中所涉及的 事 方，使用任何 网页 浏览器在本地主光盘或通过互联网（ 内联网 和 外联外 ）。  导言  以知识为基础的系统，是维护本组织内的知识和为建设公司 1企业 生存 的理想技术。它在不同的部门，纪律，组织知识也扮演 着 一个 的 重要作用。信息技术消 除 了 地域和时间的限制，通过计算机网络使得在自己的台式机或笔记本电脑 都 随时 可以查得到 信息                                        11 页  共  29 页   我们制定并实施了 一个 复杂的注塑 工艺为 给了 知识库 最佳人选启示。 这任务涉及到注塑成型塑料件 的 设计和制造，包括对产品的造型， 零件 工程 设计 ，材料选择，模具设计，模具制造（ 工艺装备 ），注塑成型， 计算机 辅助工程（ CAE）。这些 综合 学科知识的任务要求和零 件的设计 和模具，材料 属性 ，加工，计算机仿真设计能力，以及解决问成型问题决策的 能力 。 绝大多数 信息和技能的要求，为不同部门的工程师 引进 项目的同时， 也 超出了人类大脑的存储容量。它也需要一种 手段来存储和共享产品信息。发起的启蒙任务是建立一个可扩展的框架，封装，组织和传播的关键设计，加工， CAE 分析资料，塑料工程师和管理人员。利用网络为基础的技术，我们创建了一个知识 库 ，通过提供一个良好设计的用户在一个坚固的数据结构，建立一个强大的接口信息存储和检索系统。系统组件和实施过程将在下面的章节中讨论。   . 系统组件  A：源文件和数据库   知识库 的主要组成部分是信息模块（见模块和图像的信息）。我们选择的FrameMaker 源文件格式， 它是 桌面出版最流行和强大的工具之一。虽然我们认为 把FrameMaker 文件转换为可移植文档格式 （ PDF）（ 这是免费下载）， 但 我们决定 用 原有标准万维网（ WWW） 上 超文本标记语言（ HTML）格式。这一决定的原因是我们 的图像 网页质量的提高， 这是 由浏览器显示出来。我们使用第三方转换工具（ 网页 出版社）转换成 HTML 格式的 FrameMaker 文件，如图 1 所示。出版 商允许我们定义页面格式样式，以确保在生成的 HTML 文件 视觉与 感觉一致。  由于必须保持持续的 知识 未来的增长，商业 相关的 数据库应用程序已被用来管理源代码和 HTML 文件（见图 1）。每个源文件 记录 数据库中的 档案 。记录存储有关文件的（信息模块）的书名，作者，目录路径和独特的八位数字。该记录也保留了 源始资料 创建 的日期 ， 不论实验它的 HTML 副本是否已生成 ，并在知识 库 的信息模块插入标题。该数据库文件名字段中 输 入一个关键字表 示 特定项，以便我们可以自动的生成超链接索引。  B.信息模块和图像  该信息模块，它作为知识库 中 一个单一的 HTML 页面，是启蒙的基本组成单位。每个信息模块提供特定的 主题 信息，并且 可以控制 超连结至其他相关信息模块和公共网站（见图 1）。顾名思义，信息模块是模块化的，可重复使用的信息块。启蒙的用户接口是组织这些模块 进 逻辑类别并提交给用户 的 工具 。然而，这些模块的用户界面结构是完全独立。我们可以添加模块，洗牌 它 们周围，从任何一个 菜单进 入 某个 模块或完全删除模块。这些模块存储在一个位置，但无论 怎样它都 会出现。图形和数字图像中包含的启示 是由 与 Macromedia 公司的手工绘线 和 Adobe PhotoShop 的生产。它们保存在任一图形图像格式（ GIF）或联合图像专家组（ JPEG）格式。图形是 在 序列文件中创造 的 运动假象 的 分层数 GIF 的 动画  C.主要 的 主题标题                                       12 页  共  29 页   用户界面组类似 下面 的几个 主要 标题的信息模块。这些主要的标题不是一成不变的，而是可以被重新命名， 重新排列，并酌情每个版本。目前的版本的启蒙显示五个主要议题：设计，材料，加工和 C -模，故障排除。每一个主要议题进一步细分为若干顶级水平。图 2（上）， 点击 启示主页，提供了对主要议题的总体看法，并探讨在顶层部分 的 表决。用户可以点击一个单独的图形来打开该课题的主要方向和相应的主网页目录。  除 了 C 模的标题 外 ，其中包含有关用 C -模具产品（仿真实例，案例研究， Java 工具和 CAE 分析报告）的信息，其他主要议题包括一般的，非特定软件模块 ， 类似于一个塑料百科全书。 C -模报告部分提供了一种机制， 这种机制可以 为用户建立自 己的 “ 知识 ” 和可以由组织内的不同群体共享 的 CAE 分析 的 报告存档。  D.用户 界面  当前用户界面设计的启示框架采用了 Web 页面的格式，即：在浏览器窗口显示在几个不同的信息， 这浏览器 同时 由几个 独立的区域组成。正如图 2（下）中看到，每个窗口 包含 三个框架。顶部框架是 一个 包含两个菜单栏标题行：第 1 行中的导航按钮和第 2行中的主题标题。侧栏包含一个目录，根据用户选择更新。主窗口是保留给显示实际的主题。  E.合成树脂 数据库和搜索引擎  塑料 数据库包含超过 4000 的 热塑性树脂 ，该树脂 是一种启蒙的 专用功能部件 。流长图（显示 了 在一定 的工艺条件 下 可树脂以流动程度）， 允许 用户 支 比较树脂的流动性。我们 合并 了 一家 商业 的 搜索引擎，以便 于 搜索 基于 制造商和商品名称 的普通 分类 的 树脂。  F. Java 工具  正如在图 1 和图 2 所示（在 C 模标题 下 ），我们已经制定了 一对 Java 应用程序 ，该应用程序 转换 了多种单元系统 和估算的塑料零部件的成本。用户可以从他们的 Web 浏览器启动这些平台 独立的 Java 工具。  G.导航系统  为了帮助用户快速检索启示的信息，我们已经实现了 一个 如图 1 和图 2（上） 所示的导航系统，  如上所述，顶栏包含所有主题和导航选项 的 按钮。 点击一个 主标题或导 航按钮将打开其主窗口和在侧栏表格的主要内容页。然后，用户可以通过选择浏览的内容表中的主题标题。该主题将 打开在 主窗口。  如 图 2（下）显示浏览器窗口的状态后，用户 首先 选择在 顶档的 设计按钮，然后 从侧栏生成的内容表点击冷却系统设计。主页的设计是在主窗口可见，内容表列出了模块的信息与相关 的 冷却系统设计。  该导航按钮包括一个网站地图，这 网站地图 是一个全球性的内容层次表， 这表 帮助                                     13 页  共  29 页   用户获得相互关系主题在信息。该 索引在 另一方面平展了层次结构，并显示一个链接到相应的主题 的 关键词字母。 这 术语表给出了术语及其定义，按字母顺序排列。 搜索提供全文搜索用户指定查询的功能。搜索返回了一套有关于他们的相关主题连结加权名单。   . 最后的 商标  到目前为止，我们已经创造数百个不同主题 的 信息模块，作为启蒙信息库。我们还制定补充导航功能，并采纳了一个用于访问任何 Web 浏览器 的 主题模块的搜索引擎。我们目前的重点是开发文件管理工具， 该工具 管理由 CAE 软件项目报告生成，并加入向导形式的互动性。我们的目标是让用户能够管理他们自己产生的信息，使企业能够成为一个启示，聪明的知识管理工具。                                        14 页  共  29 页   New Manufacturing Technologies INTRODUCTION Driven by international competition and aided by application of computer technology, manufacturing firms have been pursuing two principal approaches during the 1980's: * automation, and * integration. Automation is the substitution of machine for human function； integration is the reduction or elimination of buffers between physical or organizational entities. The strategy behind manufacturing firms' application of new automation technologies is multidimensional: * to liberate human resources for knowledge work, * to eliminate hazardous or unpleasant jobs, * to improve product uniformity, and * to reduce costs and variability. The execution of that strategy has lead firms automate away simple, repetitive, or unpleasant func tions in their offices, factories, and laboratories. Integration, when used as an approach to improve quality, cost, and responsiveness to customers, requires that firms find ways to reduce physical, temporal, and organizational barriers among various functions. Such buffer reduction has been implemented by the elimination of waste, the substitution of information for inventory, the insertion of computer technology, or some combination of these. In most process industries - oil refining and papermaking, for example - automation and integration have been critical trends for decades. However, in discrete goods manufacture - electronics and automobiles, for example - significant movement in these directions is a recent phenomenon in the United States. This chapter defines, examines, and illustrates the application of technologies that support the trends toward more automation and integration in discrete goods manufacturing. We begin with a discussion of the technological hardware and software that has been evolving. We then look at six management challenges that must be addressed to support these trends. And, finally, we look at the issue of economic evaluation the new technologies. AUTOMATION IN MANUFACTURING As characterized, for example, by Toshiba, in their OME Works facility, automation in manufacturing can be divided into three categories: *factory automation, *engineering automation, and *planning and control automation. Automation in these three areas can occur independently, but coordination among the three, as is being pursued by this Toshiba facility, drives opportunities for computer integrated manufacturing, discussed below.                                      15 页  共  29 页   Factory Automation Although software also plays a critical role, factory automation is typically described by the technological hardware used in manufacturing: robots, numerically controlled (NC) machine tools, and automated material handling systems. Increasingly, these technologies are used in larger, integrated systems, known as manufacturing cells or flexible manufacturing syste ms (FMS). The term robot refers to a piece of automated equipment, typically programmable, that can be used for moving material to be worked on (pick and place) or assembling components into a larger device. Robots are also used to substitute for direct human labor in the use of tools or equipment, as is done, for example, by a painting robot, or a welding robot, which both positions the welder and welds joints and seams. Robots can vary significantly in complexity, from simple single-axis programmable controllers to sophisticated multi-axis machines with microprocessor control and real-time, closed-loop feedback and adjustment. A numerically-controlled (NC) machine tool is a machine tool that can be run by a computer program that directs the machine in its operations. A stand-alone NC machine needs to have the workpieces, tools, and NC programs loaded and unloaded by an operator. However, once an NC machine is running a program on a workpiece, it requires significantly less operator involvement than a manually operated machine. A CNC (computer numerically-controlled) machine tool typically has a small computer dedicated to it, so that programs can be developed and stored locally. In addition, some CNC tools have automated parts loading and tool changing. CNC tools typically have real-time, on-line program development capabilities, so that operators can implement engineering changes rapidly. A DNC (distributed numerically-controlled) system consists of numerous CNC tools linked together by a larger computer system that downloads NC programs to the distributed machine tools. Such a system is necessary for the ultimate integration of parts machining with production planning and scheduling. Automated inspection of work can also be realized with, for example, vision systems or pressure-sensitive sensors. Inspection work tends to be tedious and prone to errors, especially in very high volume manufacturing settings, so it is a good candidate for automation. However, automated inspection (especially with diagnosis capability) tends to be very difficult and expensive. This situation, where automated inspection systems are expensive to develop, but human inspection is error-prone, demonstrates the value of automated manufacturing systems with very high reliability: In such systems, inspection and test strategies can be developed to exploit the high-reliability features, with the potential to reduce significantly the total cost of manufacture and test. Automated material handling systems move workpieces among work centers, storage locations, and shipping points. These systems may include autonomous guided vehicles, conveyor systems, or systems of rails. By connecting separate points in the production system, automated material handling systems serve an integration function, reducing the time delays between different points in the production process. These systems force process layout designers to depict clearly the path of each workpiece and often make it economical to transport workpieces in small batches, providing the potential for reduced wait times and idleness. A flexible manufacturing system (FMS) is a system that connects automated workstations with a material handling system to provide a multi-stage automated manufacturing capability for a wider range of parts than is typically made on a highly-automated, non-flexible, transfer line. These systems provide flexibility because both the operations performed at each work station and the routing of parts among work stations                                      16 页  共  29 页   can be varied with software controls. The promise of FMS technology is to provide the capability for flexibility approaching that available in a job shop with equipment utilizations approaching what can be achieved with a transfer line. In fact, a FMS is a technology intermediate to these two extremes, but good management can help in pushing both frontiers simultaneously. Automated factories can differ significantly with respect to their strategic purpose and impact. Two examples, Matsushita and General Electric, may be instructive. In Osaka, Japan, Matsushita Electric Industrial Company has a plant that produces video cassette recorders (VCRs). The heart of the operation features a highly automated robotic assembly line with 100-plus work stations. Except for a number of trouble-shooting operators and process improvement engineers, this line can run, with very little human intervention, for close to 24 hours per day, turning out any combination of 200 VCR models. As of August 1988, the facility was underutilized； Matsushita was poised to increase production, by running the facility more hours per month, as demand materialized. In this situation, the marginal cost of producing more output is very low. Matsushita has effectively created a barrier to entry in the VCR industry, making it very difficult for entrants to compete on price. The second example is General Electric's Aircraft Engine Group Plant III, in Lynn, Massachusetts. This fully automated plant machines a small set of parts used by the Aircraft Engine Group's assembly plant. In contrast to Matsushita's plant, which provides strategic advantage in the VCR product market, the strategic advantage provided by GE's plant seems to address its labor market. Plant III's investment is now sunk. Eventually, it will run around the clock at very high utilization rates with a very small crew. As volume is ramped up, GE has the ability to use Plant III's capacity and cost structure as leverage with its unionized labor force which is currently making many of the parts that could eventually be transferred to Plant III. Thus, factory automation can address a variety of types of strategic needs, from product market considerations to labor market concerns. Engineering Automation From analyzing initial concepts to finalizing process plans, engineering functions that precede and support manufacturing are becoming increasingly automated. In many respects, engineering automation is very similar to factory automation； both phenomena can dramatically improve labor productivity and both increase the proportion of knowledge work for the remaining employees. However, for many companies, the economic payback structure and the justification procedures for the two technologies can be quite different. This difference between engineering automation and factory automation stems from a difference in the scale economies of the two types of technologies. In many settings, the minimum efficient scale for engineering automation is quite low. Investment in an engineering workstation can often be justified whether or not it is networked and integrated into the larger system. The firstorder improvement of the                                      17 页  共  29 页   engineer's productivity is sufficient. For justification of factory automation, the reverse is more frequently the case. The term "island of automation" has come to connote a small investment in factory automation that, by itself, provides a poor return on investment. Many firms believe that factory automation investments must be well integrated and widespread in the operation before the strategic benefits of quality, lead time, and flexibility manifest themselves. Computer-aided design is sometimes used as an umbrella term for computer-aided drafting, computer-aided engineering analysis, and computer-aided process planning. These technologies can be used to automate significant amounts of the drudgery out of engineering design work, so that engineers can concentrate more of their time and energy on being creative and evaluating a wider range of possible design ideas. For the near future machines will not typically design products. The design function remains almost completely within the human domain. Computer-aided engineering allows the user to apply necessary engineering analysis, such as finite element analysis, to propose designs while they are in the drawing board stage. This capability can reduce dramatically the need for time-consuming prototype work up and test during the product development period. Computer-aided process planning helps to automate the manufacturing engineer's work of developing process plans for a product, once the product has been designed.  Planning and Control Automation  Planning and control automation is most closely associated with material requirements planning (MRP). Classical MRP develops production plans and schedules by using product bills of materials and production lead times to explode customer orders and demand forecasts netted against current and projected inventory levels. MRP II systems (second-generation MRP) are manufacturing resource planning systems that build on the basic MRP logic, but also include modules for shop floor control, resource requirements planning, inventory analysis, forecasting, purchasing, order processing, cost accounting, and capacity planning in various levels of detail. The economic considerations for investment in planning and control automation are more similar to that for investment in factory automation than that for engineering automation. The returns from an investment in an MRP II system can only be estimated by analyzing the entire manufacturing operation, as is also the case for factory automation. The integration function of the technology provides a significant portion of the benefits. INTEGRATION IN MANUFACTURING Four important movements in the manufacturing arena are pushing the implementation of greater integration in manufacturing: * Just-in-Time manufacturing (JIT), * Design for Manufacturability (DFM), * Quality Function Deployment (QFD),  * Computer-integrated Manufacturing (CIM).                                      18 页  共  29 页   Of these, CIM is the only one directly related to new computer technology. JIT, QFD, and DFM, which are organization management approaches, are not inherently computer-oriented and do not rely on any new technological developments. We will look at them briefly here because they are important to the changes that many manufacturing organizations are undertaking and because their integration objectives are very consonant with those of CIM. Just-in-Time Manufacturing (JIT) JIT embodies the idea of pursuing streamlined or continuous-flow production for the manufacture of discrete goods. Central to the philosophy is the idea of reducing manufacturing setup times, variability, inventory buffers, and lead times in the entire production system, from vendors through to customers, in order to achieve high product quality (conformity), fast and reliable delivery performance, and low costs. The reduction of time and inventory buffers between work stations in a factory, and between a vendor and its customers, creates a more integrated production system. People at each work center develop a better awareness of the needs and problems of their predecessors and successors. This awareness, coupled with a cooperative work culture, can help significantly with quality improvement and variability reduction. Investment in technology, that is, machines and computers, is not required for the implementation of JIT. Rather, JIT is a management technology that relies primarily on persistence in pursuing continuous incremental improvement in manufacturing operations. JIT accomplishes some of the same integration objectives achieved by CIM, without significant capital investment. Just as it is difficult to quantify the costs and benefits of investments in (hard) factory automation, it is also difficult to quantify costs and benefits of a "soft" technology such as JIT. A few recent models have attempted to do such a quantification, but that body of work has not been widely applied. Design for Manufacturability (DFM) This approach is sometimes called concurrent design or simultaneous engineering. DFM is a set of concepts related to pursuing closer communication and cooperation among design engineers, process engineers, and manufacturing personnel. In many engineering organizations, traditional product development practice was to have product designers finish their work before process designers could even start theirs. Products developed in such a fashion would inevitably require significant engineering changes as the manufacturing engineers struggled to find a way to produce the product in volume at low cost with high uniformity. Ouality Function Deployment (OFD) Closely related to Design for Manufacturability is the concept of Quality Function Deployment (QFD) which requires increased communication among product designers, marketing personnel, and the ultimate product users. In many organizations, once an initial product concept was developed, long periods would pass without significant interaction between marketing personnel and the engineering designers. As a result, as the designers                                      19 页  共  29 页   confronted a myriad of technical decisions and tradeoffs, they would make choices with little marketing or customer input. Such practices often led to long delays in product introduction because redesign work was necessary once the marketing people finally got to see the prototypes. QFD formalizes interaction between marketing and engineering groups throughout the product development cycle, assuring that design decisions are made with full knowledge of all technical and market tradeoff considerations. Taken together, Design for Manufacturability and Quality Function Deployment promote integration among engineering, marketing, and manufacturing to reduce the total product development cycle and to improve the quality of the product design, as perceived by both the manufacturing organization and the customers who will buy the product. Like Just-in-Time, Design for Manufacturability and Quality Function Deployment are not primarily technological in nature. However, technologies such as Computer-aided Design can often be utilized as tools for fostering engineering/manufacturing/marketing integration. In a sense, such usage can be considered as the application of computer integrated manufacturing to implement these policy choices. Computer-interated Manufacturing (CIM) Computer-integrated manufacturing refers to the use of computer technology to link together all functions related to the manufacture of a product. CIM is therefore both an information system and a manufacturing control system. Because its intent is so all-encompassing, even describing CIM in a meaningful way can be difficult. We describe briefly one relatively simple conceptual model that covers the principal information needs and flows in a manufacturing firm. The model consists of two types of system components: * departments that supply and/or use information, and * processes that transform, combine, or manipulate information in some manner. The nine departments in the model are: 1. production 2. purchasing 3. sales/marketing 4. industrial and manufacturing engineering 5. product design engineering 6. materials management and production planning 7. controller/finance/accounting 8. plant and corporate management 9. quality assurance. The nine processes that transform, combine, or manipulate information in some manner are: 1. cost analysis 2. inventory analysis                                      20 页  共  29 页   3. product line analysis 4. quality analysis 5. workforce analysis 6. master scheduling 7. material requirements planning (MRP) 8. plant and equipment investment 9. process design and layout. To complete the specification of the model for a specific manufacturing system, one must catalog the information flows among the departments and information processes listed above. Such an information flow map can serve as a conceptual blueprint for CIM design, and can aid in visualizing the scope and function of a CIM information system. Design and implementation of a computer system to link together all of these information suppliers, processors, and users is typically a long, difficult, and expensive task. Such a system must serve the needs of a diverse group of users, and must typically bridge a variety of different software and hardware subsystems. The economic benefits from such a system come from faster and more reliable communication among employees within the organization and the resulting improvements in product quality and lead times. Since many of the benefits a CIM system are either intangible or very difficult to quantify, the decision to pursue a CIM program must be based on a long term, strategic commitment to improve manufacturing capabilities. Traditional return-on-investment evaluation procedures that characterize the decision-making processes of many U.S. manufacturing concerns will not justify the tremendous amount of capital and time required to aggressively pursue CIM. Despite the high cost and uncertainty associated with CIM implementation, most large U.S. manufacturing companies are investing some resources to explore the feasibility of using computerized information systems to integrate the various functions of their organizations. TECHNOLOGY ADOPTION CONSEQUENCES: FLEXIBILITY AND CAPITAL INTENSIVENESS As explained above, investments in factory automation and CIM move a firm in the direction of more automation and integration. To fully evaluate such investment opportunities, and to weigh the potential pay-offs against the costs,' one must consider two consequences of these technologies: 1) the flexibility of the manufacturing operation, and 2) the capital intensiveness of the operation. In this section, we look briefly at these two effects before discussing six challenges created by the new manufacturing technologies. Manufacturing flexibility - flexibility to change product mix, to change production rate, and to introduce new products - is achieved by shortening lead times within the manufacturing system and by automating setups and changeovers for different products. The importance of manufacturing flexibility for firm                                      21 页  共  29 页   competitiveness has become apparent over the past decade as the rate of economic and technological change has accelerated and as many consumer and industrial markets have become increasingly internationalized. As a consequence of this increased competition, product life cycles shorten as each firm tries to keep up with the new offerings of a larger group of industrial rivals. To survive, companies must respond quickly and flexibly to competitive threats. Therefore, firms must pay particular attention to evaluating the flexibility component of the new manufacturing technologies. Increased capital intensiveness follows directly from automation on a large scale that replaces humans with machines. A transformation to a capital intensive cost structure has two important effects. First, the manufacturing cost structure changes, from one with low fixed investment and high unit variable costs, to one with high fixed investment and low variable costs. This change will affect significantly a firm's ability to weather competitive challenges, because low variable costs allow a firm to sustain short-term profitability even in the face of severe price wars. Second, the changes in both employment levels and work responsibilities brought about by automation require significant organizational adjustment. Challenges brought about by this type of change are discussed below. SIX CHALLENGES CREATED BY THE NEW MANUFACTURING TECHNOLOGIES 1.Design and Development of CIM Systems Because of their ambitious integration objectives, CIM systems will be large, complex information systems. Ideally, the design process should start with the enunciation of the CIM  mission, followed by a statement of specific goals and tasks. Such a top-down design approach insures that the hardware and software components are engineered into a cohesive system. In addition, since the foundation of CIM consists of an integrated central database plus distributed databases, database design is critical. Also, since many people in the organization will be responsible for entering data into the system, they must understand how their functions interact with the entire system. Input from users must be considered at the design stage, and systems for checking database accuracy and integrity must be included. Hardware and software standardization must also be considered at the system design stage. At many companies, computing and database capabilities have come from a wide variety of vendors whose products are not particularly compatible. Either retooling, or developing systems to link these computers together, requires significant resources. Obviously, designing a system that will be recognized as a success, both inside and outside the organization, is a formidable challenge. Few, if any, companies have fully accomplished  this task to date.                                      22 页  共  29 页   2. Human Resource Management System As mentioned above, significant adjustment is required for an organizat ion to coalesce behind the implementation of new factory automation and CIM technology. If the new technology is not installed in a greenfield site, then layoffs are often one consequence of the change. Reductions in force are inevitably associated with morale problems for the remaining employees who may view the layoffs as a sign of corporate retreat rather than revitalization. Furthermore, human resource problems are not typically limited to simply laying off a set number of people and then just moving forward with the remaining group. CIM and automation technologies place significantly greater skill demands on the organization. Retraining and continuous education must be the rule for firms that hope to be competitive with these technologies； the firm must undergo a cultural transformation. Requirements for retraining and continuous education are at least as strong for managers and engineers who work with these new technologies as for the factory workers on the plant floor. Designing automated factories, managing automated factories, and designing products for automated factories all require supplemental knowledge and skills compared with those required for a traditional, labor intensive plant. Senior managers, who must evaluate CIM technologies, as well as the people who work with them, also can benefit significantly from education about the technologies. 3. Product Development System Factory automation and CIM can make product designers' jobs more difficult. Human-driven production systems are infinitely more adaptable than automated manufacturing systems. When designers are setting requirements for a manually built product, they can afford some sloppiness in the specifications, knowing that the human assemblers can either accomodate unexpected machining or assembly problems as they occur, or at least can recognize problems and communicate them back to the designers for redesign. In an automated setting, designers cannot rely on the manufacturing system to easily discover and recover from design errors. There are severe limits to the levels of intelligence and adaptability that can be designed into automated manufacturing systems, so product designers must have either intimate knowledge of the manufacturing system or intimate communication with those who do. Developing such a design capability in the organization is a difficult, but necessary step for achieving world-class implementation of the manufacturing system. 4. Managing Dynamic Process Improvement In most well-run, labor-intensive manufacturing systems, continuous improvement results from a highly motivated workforce that constantly strives to discover better methods for performing its work. In a highly automated factory, there are few workers to observe, test, experiment with, think about, and learn about the system and how to make it better. As a consequence, some observers claim that factory automation will mean the end of the learning curve as an important factor in manufacturing competitiveness. Such an assertion runs counter to a very long history of progress in industrial productivity, resulting from a collection of radical technological innovations, each followed by an extensive series of incremental improvements that help perfect the new technology. Most students of the subject estimate that the                                      23 页  共  29 页   accumlation of such incremental improvements accounts for as much total productivity growth as do the radical innovations. In essence, any radical innovation may be thought of as a first pass innovation which requires much more innovation before it reaches its maximum potential. To presume that factory automation and CIM will reverse this historic pattern is premature at best, and potentially very misleading to managers and implementers of these technologies. Because these technologies are so new aid so complex, one cannot expect to capture all of the relevant knowledge at the system design stage. If a firm assumes that once it is in place, the technology will not be subject to very much improvement, it will evaluate, design, and manage the system much differently than if it assumes that much benefit can be achieved by learning more about how best to use and improve the system once it is in place.(potential innovators) in it, firms who invest in this technology would be wise to assure that those people who are present are trained to discover, capture, and apply as much new knowledge as possible. In fact, discovering and exploiting opportunities for continuous improvement might be the primary reasons for firms to avoid completely unattended factories. 5. Technology Procurement Before evaluating a specific technological option, that option must be reasonably well defined. A firm needs to choose equipment and software vendors, and to decide how much of the design, production, installation, and integration of the technology will be performed with in-house staff. Many observers argue for doing as much technology development in house as possible, to minimize information leaks about the firm's process technology, and to assure a proper fit between the firm's new technology and its existing strategy, people, and capital assets. For external technology acquisition, technological options must be generated before they can be evaluated. In developing these options, a firm must consider its current assets, environment, and market position, as well as those of its competitors. Equipment vendors must be brought into the decision process. Vendor and technology evaluation criteria must be developed and utilized within the organization. 6. System Control and Performance Evaluation Once a technology investment choice has been implemented, managers typically want to track the efficacy of that investment. The shortcomings of the traditional methods for measuring manufacturing performance are widely recognized. Many of these methods can be manipulated to make current results look good at the expense of potential future results. When managers spend only a small fraction of their careers in one facility or position, they often have an incentive to engage in such manipulations. In addition, in many settings, the appropriate performance yardstick for a facility requires information on one or more competitors' facilities, on which timely, accurate data may be unavailable.                                      24 页  共  29 页   Increasingly, firms are using multidimensional measures of manufacturing performance. Rather than depending on just a profitability summary statistic, measures of quality, lead times, cost of quality, delivery performance, and total factor productivity are being utilized to evaluate performance. Despite this trend, firms could benefit from more research on how, for example, to set standards for productivity and learning rates in a highly automated, integrated environment. ECONOMIC EVALUATION FOR NEW TECHNOLOGY ADOPTION The technology adoption costs that are the most visible and easiest to estimate in advance are the up-front capital outlays for purchased hardware, software, and services. Most models consider only these costs. Also important, however, are (1) costs of laying off people whose skills will not be used in the new system, (2) costs of plant disruption caused by the introduction of new technology into an operating facility, and (3) costs of developing the human resources required to design, build, manage, maintain, and operate the new system. The benefits that flow from investment in factory automation and CIM are both tactical and strategic. These benefits relate to changes in a firm's cost structure, increased process repeatability and product conformance, lower inventories, increased flexibility, and shorter flow and communication lines. With respect to cost structure, investment in CIM and factory automation tends to represent a large up-front cost that leads to a reduction in variable costs per unit of output. This characteristic results primarily from replacement of labor by machines.  Low variable costs can provide significant competitive advantage when interfirm rivalry is high. In addition, reduced variable costs sometimes lead firms to cut prices, potentially increasing market share and revenues. The advantages arising from the increased repeatability and product conformance afforded by CIM and factory automation can also have significant competitive impact. Decreased process variability、  reduces scrap and rework costs, a source of variable cost savings that can be as important as the reduction of direct labor costs by automation. In addition, improved product conformance can provide significant sales gains in product markets. Secondary effects of improved process control include improved morale (and consequent reduced absenteeism and turnover) of employees happy to work in a system that runs well. Inventory reduction following automation and integration investments can originate from several sources. First, factory automation can reduce setup times for some types of operations, reducing the need for cycle stocks. Second, decreased process variability can decrease uncertainty in the entire manufacturing system, reducing the need for safety stocks. Third, factory integration can shorten manufacturing cycle times, reducing the in-process inventories                                      25 页  共  29 页   flowing through the system. Manufacturing flexibility is another key strategic advantage offered by CIM and factory automation. Rapid tool and equipment changeovers enable firms to quickly change product mix in response to varying market demands. In addition, NC programming and computerized process planning shorten the time to market and time to volume for new products introduced into the factory. Fully-automated manufacturing systems provide volume flexibility as well. The highly-automated Matsushita VCR factory mentioned earlier can change its output rate with relatively low and adjustment costs by increasing or decreasing the number of hours it runs each month. Because the factory's direct labor force is quite small, output declines will not lead to dramatic underemployment, and increases do not require major hiring  and training efforts. Finally, reduced lead times between work stations will lower the flow times of work between stations, thus decreasing the need for WIP in the system. As inventories and lead times are reduced, firms may increase their profit margins by charging more for rapid delivery or may increase market share by offering better service and holding prices constant. SUMMARY AND CONCLUSIONS Increased global competition and environmental volatility require that firms adapt quickly or face the possibility of extinction. Investment in automation and integration, including hardware such as automated machines and flexible manufacturing systems, software such as CIM systems, and managerial approaches such as just-in-time and design for manufacturability, can help firms to achieve and maintain competitiveness. Of course, the assets always in shortest supply are managerial vision and leadership. Manufacturing strategy creation must precede technology investment decisions, because good technology rarely saves poor management. Therefore, firms must complement their learning about technology options with information and insights about their business challenges and opportunities. Charles H. Fine teaches operations management and manufacturing strategy at MIT's Sloan School of Management. He holds Ph.d and Master's degrees from Stanford University, and a Bachelor's degree from Duke University. He has authored a number of articles on manufacturing issues, including pieces on the economics of quality improvement and on models for investment in flexible manufacturing systems. His industrial consulting, executive teaching, and research project experience includes work at Digital Equipment Corporation, Eastman Kodak, General Electric, IBM, and Motorola. A Knowledge Base System for the Design and Manufacture of                                      26 页  共  29 页   Injection-Molded Plastic Products Abstract This paper presents the development and implementation of a knowledge base system (KBS) for an important polymer molding. This KBS, named Enlighten, is built on top of web-based technology because of its ubiquity, ease of use, convenient content dissemination, its hypertext, navigation, and search capabilities, as well as the support of interactivity (via Java, JavaScript, and CGI) and multimedia (text, graphics, video, and audio). By design, the contents and tools in Enlighten can be viewed and shared by parties that are involved in the process, using any major Web browser, either locally via CDROM or through the Internet, (intranet or extranet). I. INTRODUCTION The knowledge-based system is an ideal technology for preserving knowledge within the organization and for building the corporate memory of the firm l. It also plays an important role in integrating knowledge across different departments, disciplines, and organizations. Information technology removes geographic and time barriers, making information readily assessable at ones desktop or notebook computer through networks.  We developed and implemented Enlighten for a complex injection molding procees  a perfect candidate for a KBS. The tasks involved in the design and manufacture of injection-molded plastic parts consist of product styling, part engineering, material selection, mold engineering, mold fabrication (tooling), injection molding, and computer-aided engineering (CAE). These multidisciplinary tasks require knowledge of and decision-making abilities in the design of parts and molds, material properties, processing, computer simulation, and troubleshooting of molding problems. The sheer volume of information and skills required, as engineers of different departments conduct the project concurrently, goes beyond the storage capacity of the human brain. It also requires a means to store and share product information. The Enlighten task was initiated to establish a scaleable framework that encapsulates, organizes, and disseminates crucial design, processing, and CAE analysis information to plastics engineers and managers. Using web-based technology, we have created a  knowledge base that supplies a powerful information storage and retrieval system via a well-designed user interface built upon a solid data structure. The system components and implementation process will be discussed in the following sections. . SYSTEM COMPONENTS A. Source Files and Database The major building block of Enlighten is the information module (see B. Information Modules and Images). We chose FrameMaker, one of the most popular and powerful desktop publishing tools available, as the source file format. Although we considered converting the FrameMaker files to the Portable Document Format (PDF) to be viewed by Adobe Acrobat Reader, (which is free for downloading), we decided to go with the HyperText Markup Language (HTML) format, a prevailing standard on the World Wide Web (WWW). One or the reasons for this decision was the improved quality of our graphicsrich pages when displayed by the browser. We use a third-party conversion tool (Web Works Publisher) to translate the FrameMaker files into HTML format, as depicted in Figure 1. Publisher allows us to define page-formatting styles to ensure a consistent look-and- feel in the resulting HTML documents. Since Enlighten must sustain continuous future growth, a commercial relational database application has                                      27 页  共  29 页 &nbs