外文翻譯---軟件和軟件工程

1、<p><b>　　外文翻譯:</b></p><p>　　Software and software engineering</p><p>　　----the software appearance and enumerates</p><p>　　As the decade of the 1980s began, a front

2、 page story in business week magazine trumpeted the following headline:” software: the new driving force.”software had come of age—it had become a topic for management concern. during the mid-1980s,a cover story in foreu

3、ne lamented “A Growing Gap in Software,”and at the close of the decade, business week warned managers about”the Software Trap—Automate or else.”As the 1990s dawned , a feature story in Newsweek asked ”Can We Trust Our So

4、ftware? ”and The wa</p><p>　　Software has now surpassed hardware as the key to the success of many computer-based systems. Whether a computer is used to run a business, control a product, or enable a system

5、, software is the factor that differentiates . The completeness and timeliness of information provided by software (and related databases) differentiate one company from its competitors. The design and “human friendlines

6、s” of a software product differentiate it from competing products with an otherwise similar function .</p><p>　　During the first three decades of the computing era, the primary challenge was to develop compu

7、ter hardware that reduced the cost of processing and storing data .Throughout the decade of the 1980s,advances in microelectronics resulted in more computing power at increasingly lower cost. Today, the problem is differ

8、ent .The primary challenge during the 1990s is to improve the quality ( and reduce the cost ) of computer-based solutions- solutions that are implemented with software. </p><p>　　The power of a 1980s-era mai

9、nframe computer is available now on a desk top. The awesome processing and storage capabilities of modern hardware represent computing potential. Software is the mechanism that enables us to harness and tap this potentia

10、l.</p><p>　　The context in which software has been developed is closely coupled to almost five decades of computer system evolution. Better hardware performance, smaller size and lower cost have precipitated

11、 more sophisticated computer-based systems. We’re moved form vacuum tube processors to microelectronic devices that are capable of processing 200 million connections per second .In popular books on “the computer revoluti

12、on,”O(jiān)sborne characterized a “new industrial revolution,” Toffer called the advent of </p><p>　　Figure 1-1 depicts the evolution of software within the context of. computer-based system application areas. Dur

13、ing the early years of computer system development, hardware underwent continual change while software was viewed by many as an afterthought. Computer programming was a "seat-of-the-pants" art for which few sys

14、tematic methods existed. Software development was virtually unmanaged--until schedules slipped or costs began to escalate. During this period, a batch orientation was used for mo</p><p>　　systems such as SAG

15、E. For the most part, however, hardware was dedicated to the union of, a single program that in turn was dedicated to a specific application.</p><p>　　Evolution of software</p><p>　　During the e

16、arly years, general-purpose hardware became commonplace. Software, on the other hand, was custom-designed for each application and had a relatively limited distribution. Product software(i.e., programs developed to be so

17、ld to one or more customers) was in its infancy . Most software was developed and ultimately used by the same person or organization. You wrote it, you got it running , and if it failed, you fixed it. Because job mobilit

18、y was low , managers could rest assured that you</p><p>　　Because of this personalized software environment, design was an implicit process performed in one’s head, and action was often nonexistent. During t

19、he early years we learned much about the implementation of computer-based systems, but relatively little about computer system engineering .In fairness , however , we must acknowledge the many outstanding computer-based

20、systems that were developed during this era. Some of these remain in use today and provide landmark achievements that continue to j</p><p>　　The second era of computer system evolution (Figure 1.1) spanned t

21、he decade from the mid-1960s to the late 1970s. Multiprogramming and multiuse systems introduced new concepts of human-machine interaction. Interactive techniques opened a new world of applications and new levels of hard

22、ware and software sophistication . Real-time systems could collect, analyze, and transform data form multiple sources , thereby controlling processes and producing output in milliseconds rather than minutes . Advan</p

23、><p>　　The second era was also characterized by the use of product software and the advent of "software houses." Software was developed for widespread distribution in a multidisciplinary market. Progr

24、ams for mainframes and minicomputers were distributed to hundreds and sometimes thousands of users. Entrepreneurs from industry, government, and academia broke away to "develop the ultimate software package" an

25、d earn a bundle of money.</p><p>　　As the number of computer-based systems grew, libraries of computer software began to expand. In-house development projects produced tens of thousands of program source sta

26、tements. Software products purchased from the outside added hundreds of thousands of new statements. A dark cloud appeared on the horizon. All of these programs--all of these source statements-had to be corrected when fa

27、ults were detected, modified as user requirements changed, or adapted to new hardware that was purchased. Th</p><p>　　Worse yet, the personalized nature of many programs made them virtually unmentionable. A

28、"software crisis" loomed on the horizon.</p><p>　　The third era of computer system evolution began in the mid-1970s and continues today. The distributed system--multiple computers, each performing

29、functions concurrently and communicating with one another- greatly increased the complexity of computer-based systems. Global and local area networks, high-bandwidth digital communications, and increasing demands for 

30、9;instantaneous' data access put heavy demands on software developers.</p><p>　　The third era has also been characterized by the advent and widespread use of microprocessors, personal computers, and powe

31、rful desk-top workstations. The microprocessor has spawned a wide array of intelligent products-from automobiles to microwave ovens, from industrial robots to blood serum diagnostic equipment. In many cases, software tec

32、hnology is being integrated into products by technical staff who understand hardware but are often novices in software development.</p><p>　　The personal computer has been the catalyst for the growth of many

33、 software companies. While the software companies of the second era sold hundreds or thousands of copies of their programs, the software companies of the third era sell tens and even hundreds of thousands of copies. Pers

34、onal computer hardware is rapidly becoming a commodity, while software provides the differentiating characteristic. In fact, as the rate of personal computer sales growth flattened during the mid-1980s, software-pr</p

35、><p>　　The fourth era in computer software is just beginning. Object-oriented technologies (Chapters 8 and 12) are rapidly displacing more conventional software development approaches in many application areas.

36、 Authors such as Feigenbaum and McCorduck [FEI83] and Allman [ALL89] predict that "fifth-generation" computers, radically different computing architectures, and their related software will have a profound impac

37、t on the balance of political and industrial power throughout the world. Already, "four</p><p>　　As we move into the fourth era, the problems associated with computer software continue to intensify:<

38、/p><p>　　Hardware sophistication has outpaced our ability to build software to tap hardware's potential.</p><p>　　Our ability to build new programs cannot keep pace with the demand for new prog

39、rams.</p><p>　　Our ability to maintain existing programs is threatened by poor design and inadequate resources.</p><p>　　In response to these problems, software engineering practices--the topic

40、to which this book is dedicated--are being adopted throughout the industry.</p><p>　　An Industry Perspective</p><p>　　In the early days of computing, computer-based systems were developed using

41、hardware-oriented management. Project managers focused on hardware because it was the single largest budget item for system development. To control hardware costs, managers instituted formal controls and technical standa

42、rds. They demanded thorough analysis and design before something was built. They measured the process to determine where improvements could be made. Stated simply, they applied the controls, methods, and </p><

43、p>　　In the early days, programming was viewed as an "art form." Few formal methods existed and fewer people used them. The programmer often learned his or her craft by trial and error. The jargon and challen

44、ges of building computer software created a mystique that few managers cared to penetrate. The software world was virtually undisciplined--and many practitioners of the clay loved it!</p><p>　　Today, the dis

45、tribution of costs for the development of computer-based systems has changed dramatically. Software, rather than hardware, is often the largest single cost item. For the past decade managers and many technical practition

46、ers have asked the following questions:</p><p>　　Why does it take so long to get programs finished?</p><p>　　Why are costs so high?</p><p>　　Why can't we find all errors before

47、we give the software to our customers?Why do we have difficulty in measuring progress as software is being developed?</p><p>　　These, and many other’ questions, are a manifestation of the concern about soft

48、ware and the manner in which it is developed--a concern that has tend to the adoption of software engineering practices.</p><p><b>　　譯文:</b></p><p><b>　　軟件和軟件工程</b></p

49、><p>　　——軟件的出現(xiàn)及列舉</p><p>　　在二十世紀八十年代的前十年開始的時候, 在商業(yè)周刊雜志里一個頭版故事大聲宣揚以下標題：“軟件，我們新的驅(qū)動力！”軟件帶來了一個時代------它成為了一個大家關(guān)心的主題。在八十年代中期，《財富》雜志的一個封面故事在哀嘆：“一個在發(fā)展的軟件的缺口 ”在這十年結(jié)束時,商業(yè)周刊雜志的經(jīng)理被警告只因為關(guān)于那句“軟件陷阱自動裝置或者其他”。在九十年

50、代破曉之初, 在紐約時代雜志上有個特寫詢問：“我們能信任我們的軟件嗎?” 并且華爾街時報敘述了一家專業(yè)軟件公司通過辛苦的努力的頭版文章題為“創(chuàng)造新的軟件是苦惱的任務(wù)。”這些標題和很多其他的類似的，是那種重要的電腦軟件的一種新的理解的先兆, 是新理解的作先驅(qū)計算機軟件的重要機會, 它提供并且形成的危險。</p><p>　　軟件現(xiàn)在已經(jīng)超過了硬件，作為許多計算機成功的電腦基礎(chǔ)系統(tǒng)的鑰匙。無論計算機被用來經(jīng)營業(yè)務(wù)，控

51、制一個產(chǎn)品工程，或使系統(tǒng)運行，軟件是區(qū)分的因素。信息的完整性和實時性由一個公司的不同的競爭者的不同軟件(和相關(guān)的數(shù)據(jù)庫) 提供。軟件產(chǎn)品的設(shè)計和圖案的功能來自人類，區(qū)分它從只能選其中之一的產(chǎn)品以一個相似的作用來看。那理解力和功能被插入的軟件提供，經(jīng)常區(qū)分二種相似的工業(yè)或消費品。 這就是有利有弊的軟件。</p><p>　　在計算機時代的前三十年期間, 第一位的主要挑戰(zhàn)就是發(fā)展電腦計算機硬件減少處理和存放數(shù)據(jù)的費用

52、。在八十年代的十年過程中,微觀電子學(xué)的發(fā)展導(dǎo)致計算能力逐步提高而成本卻越來越低。今天,問題不同了，在九十年代第一位的主要挑戰(zhàn)是發(fā)展電腦基礎(chǔ)解決辦法的軟件執(zhí)行質(zhì)量(和減少費用被實施以軟件的)為主。</p><p>　　一臺1980年代主要結(jié)構(gòu)主機的力量是現(xiàn)在一臺辦公桌上可利用的?，F(xiàn)代硬件的令人敬畏的處理和貯藏能力代表計算的潛力。軟件是使我們利用和輕拍這潛力的機制。</p><p><b

53、>　　軟件角色的演變</b></p><p>　　在計算機系統(tǒng)發(fā)展的五十年左右的時間里，軟件緊密地配合著其發(fā)展。更好的硬件性能，更小的尺寸，更少的花費已經(jīng)促成更好的計算機基礎(chǔ)系統(tǒng)。</p><p>　　我們移動真空電子管處理器微觀電子學(xué)的設(shè)備已有能力每秒運行二億條指令。在流行書籍上的電腦革命，有科學(xué)家描繪它為“一場新的工業(yè)革命”。有的科學(xué)家說微型電子學(xué)的發(fā)展是人類歷史上第

54、三次巨大的變化，有的預(yù)言道一場工業(yè)革命在向信息社會發(fā)展在我們的生活中將有一個意義深遠的效果，有的說道電腦控制的信息和知識將成為21世紀的焦點力量，有的提出“電子社區(qū)”將被網(wǎng)絡(luò)工作創(chuàng)造以及軟件是世界上相互交換知識的鑰匙。</p><p>　　在九十年代初，有的科學(xué)家描述到一個力量變速器在舊的建筑（政府的、教育的、工業(yè)的、經(jīng)濟的、軍用的）將一體化作為計算機或者軟件導(dǎo)致的知識的民主化。</p><p

55、>　　圖1-1 軟件的演變。</p><p>　　圖1-1 描述的是在計算機為主的系統(tǒng)應(yīng)用區(qū)域之內(nèi)軟件的演變的時間表。 在早年計算機系統(tǒng)發(fā)展期間, 硬件進行了連續(xù)變動。那時侯軟件作為事后的不被注意想法被許多人觀看了。計算機編程是少量系統(tǒng)的方法存在的藝術(shù)。軟件開發(fā)實際上是不被關(guān)注的—— 直到日程表滑倒了或費用開始升級。在這個期間, 批取向被多數(shù)系統(tǒng)使用了。也有例外的，著名的例外是交互式系統(tǒng)譬如早期的美國航空保

56、留系統(tǒng)和實時針對防御系統(tǒng)。甚至在很大程度上，硬件是執(zhí)行一個專用執(zhí)行文件程序的專用物件。</p><p>　　在早年期間, 通用硬件變得普遍。軟件，另一方面，是按客戶要求設(shè)計的為各種應(yīng)用和有相對地有限地發(fā)行。</p><p>　　軟件產(chǎn)品(i.e.,節(jié)目顯現(xiàn)出被賣對一個或更多顧客) 是在聯(lián)邦稅務(wù)局初期。多數(shù)軟件由同樣人或組織開發(fā)了和最終使用。 您寫了它, 您得到了它的運行, 并且如果它失敗了

57、, 您固定了它。由于工作流動性是降低, 如果遇到問題負責(zé)人也能放心。</p><p>　　由于這是個人性化的軟件環(huán)境, 設(shè)計是在一個人的頭腦里含蓄過地程執(zhí)行, 并且文獻經(jīng)常是不存在的。</p><p>　　在早年我們學(xué)會了關(guān)于計算機為主的系統(tǒng)的實施, 但較少學(xué)習(xí)關(guān)于計算機系統(tǒng)工程。但是, 我們必須承認被開發(fā)在這個時代期間的計算機為主的系統(tǒng)是有許多卓著之處的。這些令人傾慕的成就有很多保留在今

58、天的使用中提供繼續(xù)糾錯。</p><p>　　第二個時代計算機系統(tǒng)演變(圖1-1) 跨過了十年即從60 年代中期對70 年代晚期。</p><p>　　多元化的程序和多用戶系統(tǒng)介紹了人與機器互相作用的新概念。交互式技術(shù)打開了應(yīng)用硬件和軟件優(yōu)雅新水平的一個新世界。實時系統(tǒng)能收集、分析，并且變換數(shù)據(jù)表多個來源，因此控制過程和生產(chǎn)產(chǎn)品在毫秒而不是分鐘。其優(yōu)點在網(wǎng)上存貯導(dǎo)致了數(shù)據(jù)庫管理系統(tǒng)的第一代

59、。 </p><p>　　第二個時代為軟件公司出現(xiàn)并且描繪產(chǎn)品軟件的用途。軟件為普遍發(fā)行在一個多重學(xué)科的市場上這個目的而被開發(fā)了。軟件為計算機主機和微型計算機吸引了上百和甚至數(shù)以萬計的用戶。</p><p>　　從此，企業(yè)家從產(chǎn)業(yè)、政府以及學(xué)術(shù)界打破了“開發(fā)最后軟件包”和贏得捆綁金錢的模式。 </p><p>　　如同計算機為主的系統(tǒng)的數(shù)量在增長一樣, 計算機軟件圖

60、書館開始擴展。機構(gòu)內(nèi)部的發(fā)展項目導(dǎo)致了成千上萬個程序源語句。</p><p>　　被購買的軟件產(chǎn)品從外面增加了成千上萬個的新聲明。但是猶如一朵黑暗的云彩出現(xiàn)在天際，所有這些程序——所有這些有一些應(yīng)用是產(chǎn)生的缺點來源狀態(tài)被查出了被改, 當(dāng)用戶要求修改則改變, 或適應(yīng)被購買的新硬件。 這些活動集體叫做軟件維護。在軟件維護上工作人員花費了很多的功夫，但是軟件還是以驚人的比率吸收資源得到資源。</p>&l

61、t;p>　　更糟糕的是, 許多程序的個人化的本質(zhì)使他們潛伏的盟友失去了運轉(zhuǎn)的可靠性。一個“軟件危機”在世界上隱約地出現(xiàn)了。</p><p>　　計算機系統(tǒng)演變第三個時代開始在70 年代中期直到今天。 分配系統(tǒng)—— 多臺計算機, 各一致地起作用并且執(zhí)行通信，很大地增加了計算機為主的系統(tǒng)的復(fù)雜。</p><p>　　全球性和地區(qū)網(wǎng)絡(luò), 高帶寬數(shù)字通信,已經(jīng)在軟件開發(fā)商那里對瞬間數(shù)據(jù)存取的

62、增長的需求投入了重大需求。</p><p>　　第三個時代為對微處理器的出現(xiàn)和以及其普遍用途, 個人計算機，以及強有力的小規(guī)模工作站。</p><p>　　微處理器產(chǎn)生了大多智能產(chǎn)品，比如從汽車到微波爐, 從產(chǎn)業(yè)機器人到血液清液診斷設(shè)備。在許多情況下, 軟件技術(shù)是聯(lián)合了解硬件的產(chǎn)品的技術(shù)職員開發(fā)的，但經(jīng)常是新手在開發(fā)軟件。</p><p>　　個人計算機是許多軟件公

63、司成長的催化劑。如果說第二個時代被賣的是上百或數(shù)以萬計的軟件公司他們的程序的拷貝, 第三時代出售就是十和甚而成千上萬個的拷貝的軟件公司。</p><p>　　當(dāng)軟件提供區(qū)分的特征的時候，個人計算機硬件迅速地成為商品。實際上, 作為個人計算機銷售成長率被鋪平在80 年代中期期間, 軟件產(chǎn)品銷售還在繼續(xù)增長。許多人在產(chǎn)業(yè)和在軟件上做購買軟件花費的金錢比他們買的在家會運行的計算機更多。</p><p

64、>　　第四個時代對計算機軟件來說是正義起點。面向?qū)ο蟮募夹g(shù)(章節(jié)8 和12) 在許多應(yīng)用范圍迅速地偏移更加常規(guī)的軟件開發(fā)方法。</p><p>　　作者譬如[ FEI83 ] 以及Allman [ ALL89 ] 預(yù)言"五世代" 計算機, 計算的程序根本不同, 并且他們的相關(guān)軟件在世界各地將對政治和工業(yè)力量的平衡方面產(chǎn)生深刻的沖擊。</p><p>　　現(xiàn)在，“軟

65、件開發(fā)的第四代”技術(shù)(在這個章節(jié)里以后會討論) 改變方式軟件社區(qū)修造了計算機程序的一些段。最后，專家系統(tǒng)和人工智能軟件從實驗室進入了現(xiàn)實世界中的廣泛問題，成為其實際應(yīng)用的軟件。人工神經(jīng)網(wǎng)絡(luò)軟件開辟了扣人心弦的類似人類信息處理能力。</p><p>　　如同我們進入第四個時代的時候，計算機軟件的問題繼續(xù)增強:</p><p>　　問題一： 很多性能優(yōu)越的硬件已經(jīng)超過了我們建立軟件控制硬件的潛

66、力及能力。</p><p>　　問題二： 我們建立新程序的能力無法與對新程序的需求同步。</p><p>　　問題三： 由于粗劣的設(shè)計和不充分的資源，我們維護現(xiàn)有的程序的能力受到了威脅。</p><p>　　這些問題的的回應(yīng), 被采取在產(chǎn)業(yè)過程中。軟件工程實踐——這本書的題目是熱忱的。</p><p><b>　　產(chǎn)業(yè)透視</

67、b></p><p>　　在早期計算, 程序員開發(fā)了計算機為主的系統(tǒng)使用被安置的硬件管理。 項目負責(zé)人集中于硬件因為這是為系統(tǒng)開發(fā)唯一最大的預(yù)算項目?？刂朴布M用, 負責(zé)人設(shè)立了正式控制和技術(shù)標準。</p><p>　　在某事被建立了之前，他們會要求詳盡的分析和設(shè)計。 他們測量過程確定何處能做改進。簡單地陳述，他們申請了控制、方法，以及我們認可當(dāng)硬件工程學(xué)的工具。但是很悲哀的是, 軟

68、件經(jīng)常只是少許事后的想法。</p><p>　　在早期, 編程被觀看者觀看了但是只是作為“藝術(shù)形式”。少量正常方法存在了但是也只有很少人使用了他們。</p><p>　　很多程序員經(jīng)常地經(jīng)過反復(fù)試驗大家的編程藝術(shù)，然后學(xué)會這些復(fù)雜的編程工藝。計算機軟件?？菩g(shù)語的大廈的雜亂無章和攻擊性大廈挑戰(zhàn)了少量程序員仔細透視這一奧妙。軟件世界是真正的無紀律的—那個時期很多專業(yè)人員愛上了軟件世界!<

69、/p><p>　　今天, 費用的發(fā)行被計算機為主的系統(tǒng)的發(fā)展顯著改變了。 軟件, 而不是硬件, 經(jīng)常是最大的唯一費用項目。過去十年經(jīng)理和許多技術(shù)實習(xí)者請求以下問題:</p><p>　　為什么它采取如此長期時間得到被完成的編程?</p><p>　　為什么費用是很高的?</p><p>　　為什么我們不可以發(fā)現(xiàn)所有錯誤在我們把軟件給我們的顧客之前