【正文】 應(yīng)應(yīng)用計算機輔助設(shè)計和計算機輔助制造集成（ CAD/CAM）可以克服調(diào)整費用高的問題。生產(chǎn)成本的一些變化是由于固定成本相對于可變成本的比值變化。此后，數(shù)字計算機被應(yīng)用直接對許多數(shù)控機床產(chǎn)生輸入直接數(shù)字控制，對具有更加專用控制的計算機數(shù)字控制產(chǎn)生輸入。 亨利 .福特所做的貢獻與泰勒的有所不同，福特為其汽車主要 零件制造廠研制并改進了裝類生產(chǎn)線?？傊?，整個工程和制造時代是以使用集成的CAD/CAM 方法為標志的。隨著數(shù)控技術(shù)的出現(xiàn)，需要能自動生成加工林所須的刀具路徑。 提高設(shè)計水平。更切實的說，工業(yè)上最早研制和使用的 CAD 系統(tǒng)應(yīng)屬于計算機輔助繪圖系統(tǒng)。而機床控制指令必須連續(xù)不斷的加以處理，許多情況下其處理的時間僅為幾微秒或幾納秒。其次，用計算機輔助繪圖軟件和繪圖機繪制零件及明細表。 the reason being the volume will not offset the setup expenses. The manufacturing alternative t6 produce those parts is through the use of flexible manufacturing systems (FMSs). These systems are nothing more than programmable job shops. However, a major economic expense still exists before one can begin employing such systems more fully. TIlis obstacle is that a considerable setup (plan ning ) expense is still required. The alternative to eliminate this expensive setup is through integration of puteraided design and puteraided manufacturing (CAD/CAM). In an integrated CAD/ CAM system, parts will be detailed using a CAD system. 39。s CAD systems, designing (againg a rea.39。. Many mercial software packages are available for scheduling, inventory control, and shop floor control, including materials requirements planning (MRP) systems. At the shop floor level puters are used extensively for the control and monitoring of individual machines. There is a difference in the time scale required for processing data and the issuing of instructions for these various applications of puters in the product cycle. For example, design and processplanning functions are carried out once for each new product and the time scale required is on the order of weeks to years for the petion of the task . Scheduling and production period cusually one week,throughout the year .at the machinecontrol level instructions must be issued continually with a time scale of microor nanoseconds in many cases. One of the major objectives of CAM is the integration of the various activities in the product cycle into one unified system, in which data is transfened from one function to another automatically. This leads to the concept of puterintegrated manufacture ( CIM), with the final objective being the paperless factory. Several developments have taken place, but no totally integrated CIM systems have yet been achieved. Since the design and processplanning functions are carned out once in the product cycle, these are the most suitable functions for integration. This integration is particularly desirable because the geometric data generated during the design process is one of the basic inputs used by process plannipg when determining appropriate manufacturing sequences and work plans174。s contributions took a different turn from Taylor39。當產(chǎn)品投入生產(chǎn)后，安排生產(chǎn)時間，控制生產(chǎn)，確定加工和裝配每個零件中每個環(huán)節(jié)的先后順序和所需要的時間，使之符合總體的生產(chǎn)進度安排，然后根據(jù)此安排進行實際生產(chǎn)和產(chǎn)品質(zhì)量控制，最后將成品交付給用戶。 為生產(chǎn)過程中各種計算機的應(yīng)用處理數(shù)據(jù)、生成指令所需的時間長短不同。 具有計算機輔助制造功能的產(chǎn)品設(shè)計周期 計算機輔助設(shè)計及計算機繪圖及自動打開文件；基本的產(chǎn)品生產(chǎn)周期；產(chǎn)品的構(gòu)思；繪圖，擁護及市場要求；訂購新設(shè)備及工藝裝備；工藝過程設(shè)計；計算機輔助工藝設(shè)計；質(zhì)量控制；生產(chǎn)；作業(yè)計劃；每個產(chǎn)品的生產(chǎn)周期為幾周至數(shù)年；計算機輔助質(zhì)量控制；計算機控制機器人；機械設(shè)備等；計算機制定作業(yè)計劃。由于使用容易交換的幾何模型進行設(shè)計，可將從構(gòu)思設(shè)計到完成產(chǎn)品說明書所須的設(shè)計總的時間減少一個數(shù)量級?？梢栽趲缀涡螤畹幕A(chǔ)上對零件的編碼，能夠調(diào)用類似的零件來設(shè)計和規(guī)范新的零件。確定加工方案的過程中，也可能要設(shè)計專用的工藝裝備，夾具等。泰勒倡導了“科學管理”的研究，研究了包含人和機床的生產(chǎn)方法。美國空軍認識到生產(chǎn)這些專用設(shè)備所需要的時間以及只對加工順序作 小的邊動所需要的時間都過大。在 20 世紀 50 年代，人們估計，隨著飛機飛速的提高，飛機的再造成本將成比例的增加（因為飛機的幾何形狀復雜性提高），這就導致NC 技術(shù)的發(fā)展。制造廠應(yīng)選擇柔性制造系統(tǒng)（ FMS）生產(chǎn)這些產(chǎn)品，這些系統(tǒng)無非就是可編程序的加工車間。 。生產(chǎn)成本的變化并不是由這種固定成本與可變成本簡單關(guān)系反映出來的，而通常取決于不同的制造技術(shù)，即大批量生產(chǎn)的自動線技術(shù)及小批量生產(chǎn)的車間生產(chǎn)技術(shù)。例如19 世紀的技術(shù)進步帶來了高精加工的要求（由此發(fā)明了很多新機床，機床設(shè)計的更合理，并形成了一些新的加工方法）。 盡管制造業(yè)持續(xù)發(fā)展，但直到 20 世紀 50 年代才出現(xiàn)了第二次重大進展。二十世紀初期，美國人民生活水平提高，增加了個人財富，從而又導致了人們對耐用品的需求增多。 有趣的是，在二十年前如果要設(shè)計出幾何形