计算机系——外文翻译(中英对照,3000汉字左右)

计算机系——外文翻译(中英对照,3000汉字左右)
计算机系——外文翻译(中英对照,3000汉字左右)

毕业设计(论文)外文资料翻译

系别计算机信息与技术系

专业计算机科学与技术

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附件 1. 原文; 2. 译文

2012年3月

History of computing

Main article: History of computing hardware

The first use of the word "computer" was recorded in 1613, referring to a person who carried out calculations, or computations, and the word continued with the same meaning until the middle of the 20th century. From the end of the 19th century the word began to take on its more familiar meaning, a machine that carries out computations.

Limited-function early computers

The Jacquard loom, on display at the Museum of Science and Industry in Manchester, England, was one of the first programmable devices.

The history of the modern computer begins with two separate technologies, automated calculation and programmability, but no single device can be identified as the earliest computer, partly because of the inconsistent application of that term. A few devices are worth mentioning though, like some mechanical aids to computing, which were very successful and survived for centuries until the advent of the electronic calculator, like the Sumerian abacus, designed around 2500 BC of which a descendant won a speed competition against a modern desk calculating machine in Japan in 1946, the slide rules, invented in the 1620s, which were carried on five Apollo space missions, including to the moon and arguably the astrolabe and the Antikythera mechanism, an ancient astronomical computer built by the Greeks around 80 BC. The Greek mathematician Hero of Alexandria (c. 10–70 AD) built a mechanical theater which performed a play lasting 10 minutes and was operated by a complex system of ropes and drums that might be considered to be a means of deciding which parts of the mechanism performed which actions and when. This is the essence of programmability.

Around the end of the 10th century, the French monk Gerbert d'Aurillac brought back from Spain the drawings of a machine invented by the Moors that answered either Yes or No to the questions it was asked. Again in the 13th century, the monks Albertus Magnus and Roger Bacon built talking androids without any further development.

In 1642, the Renaissance saw the invention of the mechanical calculator, a device that could perform all four arithmetic operations without relying on human intelligence. The mechanical calculator was at the root of the development of

computers in two separate ways. Initially, it was in trying to develop more powerful and more flexible calculators that the computer was first theorized by Charles Babbage and then developed. Secondly, development of a low-cost electronic calculator, successor to the mechanical calculator, resulted in the development by Intel of the first commercially available microprocessor integrated circuit.

First general-purpose computers

In 1801, Joseph Marie Jacquard made an improvement to the textile loom by introducing a series of punched paper cards as a template which allowed his loom to weave intricate patterns automatically. The resulting Jacquard loom was an important step in the development of computers because the use of punched cards to define woven patterns can be viewed as an early, albeit limited, form of programmability.

In 1837, Charles Babbage was the first to conceptualize and design a fully programmable mechanical computer, his analytical engine. Limited finances and Babbage's inability to resist tinkering with the design meant that the device was never completed ; nevertheless his son, Henry Babbage, completed a simplified version of the analytical engine's computing unit (the mill) in 1888. He gave a successful demonstration of its use in computing tables in 1906. This machine was given to the Science museum in South Kensington in 1910.

In the late 1880s, Herman Hollerith invented the recording of data on a machine-readable medium. Earlier uses of machine-readable media had been for control, not data. "After some initial trials with paper tape, he settled on punched cards ..." To process these punched cards he invented the tabulator, and the keypunch machines. These three inventions were the foundation of the modern information processing industry. Large-scale automated data processing of punched cards was performed for the 1890 United States Census by Hollerith's company, which later became the core of IBM. By the end of the 19th century a number of ideas and technologies, that would later prove useful in the realization of practical computers, had begun to appear: Boolean algebra, the vacuum tube (thermionic valve), punched cards and tape, and the teleprinter.

During the first half of the 20th century, many scientific computing needs were met by increasingly sophisticated analog computers, which used a direct mechanical or electrical model of the problem as a basis for computation. However, these were not programmable and generally lacked the versatility and accuracy of modern digital

computers.

Alan Turing is widely regarded as the father of modern computer science. In 1936 Turing provided an influential formalisation of the concept of the algorithm and computation with the Turing machine, providing a blueprint for the electronic digital computer. Of his role in the creation of the modern computer, Time magazine in naming Turing one of the 100 most influential people of the 20th century, states: "The fact remains that everyone who taps at a keyboard, opening a spreadsheet or a word-processing program, is working on an incarnation of a Turing machine".

EDSAC was one of the first computers to implement the stored-program (von Neumann) architecture.

Die of an Intel 80486DX2 microprocessor (actual size: 12×6.75 mm) in its packaging.

The Atanasoff–Berry Computer (ABC) was the world's first electronic digital computer, albeit not programmable. Atanasoff is considered to be one of the fathers of the computer.Conceived in 1937 by Iowa State College physics professor John Atanasoff, and built with the assistance of graduate student Clifford Berry, the machine was not programmable, being designed only to solve systems of linear equations. The computer did employ parallel computation. A 1973 court ruling in a patent dispute found that the patent for the 1946 ENIAC computer derived from the Atanasoff–Berry Computer.

The first program-controlled computer was invented by Konrad Zuse, who built the Z3, an electromechanical computing machine, in 1941. The first programmable electronic computer was the Colossus, built in 1943 by Tommy Flowers.

George Stibitz is internationally recognized as a father of the modern digital computer. While working at Bell Labs in November 1937, Stibitz invented and built a relay-based calculator he dubbed the "Model K" (for "kitchen table", on which he had assembled it), which was the first to use binary circuits to perform an arithmetic operation. Later models added greater sophistication including complex arithmetic and programmability.

A succession of steadily more powerful and flexible computing devices were constructed in the 1930s and 1940s, gradually adding the key features that are seen in modern computers. The use of digital electronics (largely invented by Claude Shannon in 1937) and more flexible programmability were vitally important steps, but defining one point along this road as "the first digital electronic computer" is difficult.

Notable achievements include. Konrad Zuse's electromechanical "Z machines". The Z3 (1941) was the first working machine featuring binary arithmetic, including floating point arithmetic and a measure of programmability. In 1998 the Z3 was proved to be Turing complete, therefore being the world's first operational computer.

The non-programmable Atanasoff–Berry Computer (commenced in 1937, completed in 1941) which used vacuum tube based computation, binary numbers, and regenerative capacitor memory. The use of regenerative memory allowed it to be much more compact than its peers (being approximately the size of a large desk or workbench), since intermediate results could be stored and then fed back into the same set of computation elements.

The secret British Colossus computers (1943), which had limited programmability but demonstrated that a device using thousands of tubes could be reasonably reliable and electronically reprogrammable. It was used for breaking German wartime codes.

The Harvard Mark I (1944), a large-scale electromechanical computer with limited programmability.

The U.S. Army's Ballistic Research Laboratory ENIAC (1946), which used decimal arithmetic and is sometimes called the first general purpose electronic computer (since Konrad Zuse's Z3 of 1941 used electromagnets instead of electronics). Initially, however, ENIAC had an inflexible architecture which essentially required rewiring to change its programming.

Stored-program architecture

Replica of the Small-Scale Experimental Machine (SSEM), the world's first stored-program computer, at the Museum of Science and Industry in Manchester, England

Several developers of ENIAC, recognizing its flaws, came up with a far more flexible and elegant design, which came to be known as the "stored-program architecture" or von Neumann architecture. This design was first formally described by John von Neumann in the paper First Draft of a Report on the EDV AC, distributed in 1945. A number of projects to develop computers based on the stored-program architecture commenced around this time, the first of which was completed in 1948 at the University of Manchester in England, the Manchester Small-Scale Experimental Machine (SSEM or "Baby"). The Electronic Delay Storage Automatic Calculator

(EDSAC), completed a year after the SSEM at Cambridge University, was the first practical, non-experimental implementation of the stored-program design and was put to use immediately for research work at the university. Shortly thereafter, the machine originally described by von Neumann's paper—EDV AC—was completed but did not see full-time use for an additional two years.

Nearly all modern computers implement some form of the stored-program architecture, making it the single trait by which the word "computer" is now defined. While the technologies used in computers have changed dramatically since the first electronic, general-purpose computers of the 1940s, most still use the von Neumann architecture.

Beginning in the 1950s, Soviet scientists Sergei Sobolev and Nikolay Brusentsov conducted research on ternary computers, devices that operated on a base three numbering system of ?1, 0, and 1 rather than the conventional binary numbering system upon which most computers are based. They designed the Setun, a functional ternary computer, at Moscow State University. The device was put into limited production in the Soviet Union, but supplanted by the more common binary architecture.

Semiconductors and microprocessors

Computers using vacuum tubes as their electronic elements were in use throughout the 1950s, but by the 1960s had been largely replaced by semiconductor transistor-based machines, which were smaller, faster, cheaper to produce, required less power, and were more reliable. The first transistorised computer was demonstrated at the University of Manchester in 1953. In the 1970s, integrated circuit technology and the subsequent creation of microprocessors, such as the Intel 4004, further decreased size and cost and further increased speed and reliability of computers. By the late 1970s, many products such as video recorders contained dedicated computers called microcontrollers, and they started to appear as a replacement to mechanical controls in domestic appliances such as washing machines. The 1980s witnessed home computers and the now ubiquitous personal computer. With the evolution of the Internet, personal computers are becoming as common as the television and the telephone in the household.

Modern smartphones are fully programmable computers in their own right, and as of 2009 may well be the most common form of such computers in existenc.

历史的计算

主要文章:计算机硬件的历史

在第一次使用“计算机”这个词被记录在1613年,指的是对一个人进行了计算,或计算,与词的意思相同,直到继续20世纪中期。19世纪末开始其更熟悉的含义,一个机器进行计算。

Limited-function早期计算机

雅卡尔的展览上,在科学工业博物馆在曼彻斯特,是英国最早的一种可编程设备。

现代计算机的历史开始于两个独立的技术,自动计算和可编程,但没有一种单一的设备可以看成是最早的电脑,部分的原因是由于不应用那个术语。一些设备值得一提的是,虽然喜欢一些机械复制计算,很成功,并且存活了几个世纪,来临的电子计算器,像苏美尔算盘,大约在公元前2500年左右的设计赢得竞争的后代对现代书桌速度计算机器在1946年日本滑动规则,起源于1620年代,进行了五阿波罗太空机构,包括月球等机制,一个古老的天文计算机建造大约在公元前80年的希腊人。亚历山大的希腊数学家的英雄(公元前10 -公元70年)建造了一个机械剧院演了一出剧的持续10分钟的时间,是一个复杂的旋转系统操作的绳索和桶,可能会被认为是一种手段决定的哪个部位进行行为和机理的时候。这是可编程的本质。

十世纪末,法国僧侣带回来斯韦二氏西班牙画的机器发明的,要么摩尔人回答是或否的问题。在13世纪,僧侣们Albertus马格努斯和罗杰·培根说没有任何建造机器人的进一步发展。

1642年,文艺复兴时期的看见发明的机械计算器,一种装置能完成所有的四个算术运算,不用依赖人类的智力。机械计算器的根源是电脑的发展有两种方式。最初,是在试图发展更强大和更灵活的计算器,电脑是第一个被人们记得查尔斯·巴贝奇,然后理论发展。其次,开发的一种低成本的电子计算器继任者、机械计算器,造成了发展的第一个商业化可用英特尔处理器集成电路。

第一次通用计算机

1801年,约瑟夫玛丽做了一个改进提花织机介绍纺织一系列打孔纸质卡作为一个模板使织机编织自动错综复杂的模式。结果提花机是一个重要的发展历程中的电脑,因为使用穿孔卡片来定义编织模式可被看作是早,虽然有限,可编程的形式。

1837年,查尔斯·巴巴奇是第一个构思和设计一个完全可编程机械计算机,

他的分析引擎。有限的财政和巴巴奇未能抵抗摆弄设计意味着装置是根本没完成的;然而他的儿子,亨利·巴巴奇,完成了一个简化版本的分析引擎的运算单元(厂)于1888年。他给了一个成功的示范用于计算表于1906年。这台机器是给科学博物馆位于南肯辛顿于1910年。

在1880年代晚期,赫尔曼。霍尔瑞斯发明了记录的一种机器可以阅读的数据中。机器的使用媒体早些时候被控制,没有数据。“经过一段时间的试验,他住在纸带上穿孔卡片…“处理这些穿孔卡片他发明了针孔制表机。这三个发明是基础的现代信息加工业。大型自动化的数据处理进行了穿孔卡片为1890年美国人口普查由霍勒里斯的公司,后来成为了IBM的核心。19世纪末大量的新技术、新思路,后来被证明是有用的计算机实现的实践,已经开始出现:布尔代数,真空管(计算机阀),穿孔卡片和磁带,电传打字机。

在20世纪初,许多科学计算需要受到了越来越复杂的模拟计算机,它通过直接机械或电气模型为基础计算问题。然而,这不是编程,通常缺乏的通用性和准确性的现代数字计算机。

阿兰·图灵就被广泛认为是现代计算机科学之父。在1936年提供了一个有影响力的正规化涂林的概念和计算方法与涂林机器,提供电子数字计算机的蓝图。他的角色在创作现代计算机的时候,《时代》杂志在20世纪命名图灵的100位最具影响力的人物之一,声明:“事实是,每个人在一个键盘,打开水龙头电子数据表或一个字处理程序,正在涂林的化身”。

这Zuse虚拟的某种知识世界,1941年,被认为是世界上的第一个工作可编程、全自动计算机器。

EDSAC是其中第一个计算机来实现stored-program(冯。诺依曼)的建筑。

一个英特尔80486 DX2微处理器(实际尺寸:12×6.75毫米),在它的包装。 Atanasoff-Berry的计算机(ABC)是世界上最早的电子数字计算机,但不可编程的。阿坦那索夫被认为是其中一位电脑之父。它孕育于1937年由爱荷华州立大学物理学教授约翰?阿坦那索夫,修筑协助研究生克利夫?贝瑞,机器没有可编程的,只有解决系统在设计线性方程组。并采用计算机并行处理能力。1973年专利纠纷的法院判决书中发现的专利1946 ENIAC计算机来源于Atanasoff-Berry电脑。

第一个程控计算机发明的康拉德祖萨、谁建的虚拟的某种知识世界,机电一体化计算机器,在1941年。第一个可编程电子计算机是庞然大物,始建于1943年由汤米·花朵。

乔治是国际公认的父亲的现代数字计算机。在工作时,在贝尔实验室在1937年11月,Stibitz发明,搭建了一个基于继电器的计算器他称为“模型K”(“厨

房桌子”,但他聚集它),这是第一个使用二进制电路执行算术运算。最近的模型更大的复杂性增加包括复杂的算术和可编程。

一个接一个的稳定更强大和灵活的计算装置建于1940年代和1930年代,逐渐增加的主要特点是出现在现代的计算机。使用数码电子(主要是在1937年发明的克劳德夏侬)和更灵活的可编程是至关重要的步骤,但确定一个点沿着这条道路是“第一个电子数字计算机”是困难的。显著的成果包括。

康拉德·祖萨机电“Z机器”。这个虚拟的某种知识世界(1941)是第一个以二进制算术工作机,包括浮点运算和可编程的一个衡量标准。在1998年,虚拟的某种知识世界被证明是图灵完整,因此被世界上第一个操作电脑。

可编程的的计算机(开始于1937年,在1941年完成)采用真空管基础计算、二进制数字,和蓄热式电容器的记忆。使用蓄热式记忆允许他的作品被更紧凑的比它的同行出色(正在约的体积有一个大桌子或平台,因为中间结果可以存储,然后反馈到相同的一组计算元素。

英国的秘密"巨神像"电脑(1943年),有限但显示装置可编程使用成千上万的管可以合理可靠和电子系统中可编程门。它是用来破坏德国战时的代码。

哈佛马克一世(1944年),一个大型机电式计算机有限的可编程。

美国军队的弹道研究实验室ENIAC(1946),采用十进制算法和有时被称为第一次通用电子计算机(因为康拉德?祖萨的虚拟的某种知识世界1941使用电磁铁代替电子)。最初,然而,ENIAC有一个呆板的建筑本质要求改变其重新编程。

小规模的实验机的复制品(SSEM),世界上第一个可存储电脑,在科学工业博物馆在曼彻斯特,英格兰电子计分数字计算机的几个开发商,承认其缺点,想出了一个更加灵活和优雅的设计,这后来被称作“存储建筑”或冯·诺依曼结构。本设计是第一个正式的描述由约翰·冯·纽曼在纸的初稿EDVAC的一份报告显示,分布在1945年。许多项目建立计算机基于存储建筑开始在这个时候,其中第一本于1948年完工,在英国曼彻斯特大学的,这位小型实验机(SSEM或“宝贝”)。电子延迟存储自动计算器(EDSAC),完成后一年SSEM在剑桥大学,是第一个实用的、non-experimental设计和实施可存储计算机立即在投入使用为研究在本校工作。不久,这台机器原本冯。诺依曼的描述完成的,却没有看见paper-EDVAC-was 全职使用额外的两年。

几乎所有的现代计算机执行一些形式的stored-program架构,使之成为单一对方“计算机”这个词现在定义。而技术用于电脑有了显著的变化自从第一电子、通用计算机的1940年代,大部分仍然使用冯·诺依曼体系结构。

从1950年代开始,苏联科学家谢尔盖·萨辛进行研究,对三元Brusentsov 计算机、设备运行在一个基地,三个编码系统的?1,0,- 1,而不是传统的二进制编

码系统在大多数电脑的基础。他们设计了Setun,功能三元电脑,在莫斯科,州立大学。该设备已经投入有限公司生产在苏联,但取代二进制建筑更常见。

半导体和微处理器

计算机使用真空管为其在使用电子元件在整个1950年代,但到了1960年代已经很大程度地取代了半导体的电晶体的机械,这些机械是更小,更快,更便宜的生产,需要更少的电力,并且他们也更可在1970年代,集成电路技术和随后而来的微处理器,如英特尔4004,进一步减少体积和成本,进一步提高计算机的速度和可靠性。在1970年代晚期,许多产品,如录像机专用电脑中被称为微控制器,他们开始出现在更换到机械控制家电如洗衣机。在1980年代产生了家用电脑和现在到处都个人计算机。因特网的进化,个人电脑将成为一般的电视和电话的家务活动。

现代智能手机完全可编程计算机在他们自己的权力,在2009年很可能是最常见的计算机在手机等。

毕设外文资料翻译.

理工学院 毕业设计外文资料翻译 专业:计算机科学与技术 姓名:马艳丽 学号: 12L0752218 外文出处:The Design and Implementation of 3D Electronic Map of Campus Based on WEBGIS 附件: 1.外文资料翻译译文;2.外文原文。

附件1:外文资料翻译译文 基于WebGIS的校园三维电子地图的设计与实现 一.导言 如今,数字化和信息化是当今时代的主题。随着信息革命和计算机科学的发展,计算机技术已经渗透到科学的各个领域,并引起了许多革命性的变化,在这些科目,古代制图学也不例外。随着技术和文化的不断进步,地图变化的形式和内容也随之更新。在计算机图形学中,地理信息系统(GIS)不断应用到Web,制作和演示的传统方式经历了巨大的变化,由于先进的信息技术的发展,地图的应用已经大大延长。在这些情况下,绘图将面临广阔的发展前景。电子地图是随之应运而生的产品之一。随着计算机技术,计算机图形学理论,遥感技术,航空摄影测量技术和其他相关技术的飞速发展。用户需要的三维可视化,动态的交互性和展示自己的各种地理相关的数据处理和分析,如此多的关注应支付的研究三维地图。东北石油大学及其周边地区的基础上本文设计并建立三维电子地图。 二.系统设计 基于WebGIS的校园三维电子地图系统的具有普通地图的一般特性。通过按键盘上的箭头键(上,下,左,右),可以使地图向相应的方向移动。通过拖动鼠标,可以查看感兴趣的任何一个地方。使用鼠标滚轮,可以控制地图的大小,根据用户的需求来查看不同缩放级别的地图。在地图的左下角会显示当前鼠标的坐标。在一个div层,我们描绘了一个新建筑物的热点,这层可以根据不同的地图图层的显示,它也可以自动调整。通过点击热点,它可以显示热点的具体信息。也可以输入到查询的信息,根据自己的需要,并得到一些相关的信息。此外,通过点击鼠标,人们可以选择检查的三维地图和卫星地图。 主要功能包括: ?用户信息管理:检查用户名和密码,根据权限设置级别的认证,允许不同权限的用户通过互联网登录系统。 ?位置信息查询:系统可以为用户提供模糊查询和快速定位。

计算机专业毕业设计说明书外文翻译(中英对照)

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【机械类文献翻译】机床

毕业设计(论文)外文资料翻译 系部: 专业: 姓名: 学号: 外文出处:English For Electromechanical (用外文写) Engineering 附件:1.外文资料翻译译文;2.外文原文。 指导教师评语: 此翻译文章简单介绍了各机床的加工原理,并详细介绍了各机床的构造,并对方各机床的加工方法法进行了详细的描述, 翻译用词比较准确,文笔也较为通顺,为在以后工作中接触英 文资料打下了基础。 签名: 年月日注:请将该封面与附件装订成册。

附件1:外文资料翻译译文 机床 机床是用于切削金属的机器。工业上使用的机床要数车床、钻床和铣床最为重要。其它类型的金属切削机床在金属切削加工方面不及这三种机床应用广泛。 车床通常被称为所有类型机床的始祖。为了进行车削,当工件旋转经过刀具时,车床用一把单刃刀具切除金属。用车削可以加工各种圆柱型的工件,如:轴、齿轮坯、皮带轮和丝杠轴。镗削加工可以用来扩大和精加工定位精度很高的孔。 钻削是由旋转的钻头完成的。大多数金属的钻削由麻花钻来完成。用来进行钻削加工的机床称为钻床。铰孔和攻螺纹也归类为钻削过程。铰孔是从已经钻好的孔上再切除少量的金属。 攻螺纹是在内孔上加工出螺纹,以使螺钉或螺栓旋进孔内。 铣削由旋转的、多切削刃的铣刀来完成。铣刀有多种类型和尺寸。有些铣刀只有两个切削刃,而有些则有多达三十或更多的切削刃。铣刀根据使用的刀具不同能加工平面、斜面、沟槽、齿轮轮齿和其它外形轮廓。 牛头刨床和龙门刨床用单刃刀具来加工平面。用牛头刨床进行加工时,刀具在机床上往复运动,而工件朝向刀具自动进给。在用龙门刨床进行加工时,工件安装在工作台上,工作台往复经过刀具而切除金属。工作台每完成一个行程刀具自动向工件进给一个小的进给量。 磨削利用磨粒来完成切削工作。根据加工要求,磨削可分为精密磨削和非精密磨削。精密磨削用于公差小和非常光洁的表面,非精密磨削用于在精度要求不高的地方切除多余的金属。 车床 车床是用来从圆形工件表面切除金属的机床,工件安装在车床的两个顶尖之间,并绕顶尖轴线旋转。车削工件时,车刀沿着工件的旋转轴线平行移动或与工件的旋转轴线成一斜角移动,将工件表面的金属切除。车刀的这种位移称为进给。车

毕设外文文献翻译

xxxxxxxxx 毕业设计(论文)外文文献翻译 (本科学生用) 题目:Poduct Line Engineering: The State of the Practice 生产线工程:实践的形态 学生姓名:学号: 学部(系): 专业年级: 指导教师:职称或学位: 2011年3月10日

外文文献翻译(译成中文1000字左右): 【主要阅读文献不少于5篇,译文后附注文献信息,包括:作者、书名(或论文题目)、出版社(或刊物名称)、出版时间(或刊号)、页码。提供所译外文资料附件(印刷类含封面、封底、目录、翻译部分的复印件等,网站类的请附网址及原文】 Requirements engineering practices A precise requirements engineering process— a main driver for successful software development —is even more important for product line engineering. Usually, the product line’s scope addresses various domains simultaneously. This makes requirements engineering more complex. Furthermore, SPL development involves more tasks than single-product development. Many product line requirements are complex, interlinked, and divided into common and product-specific requirements. So, several requirements engineering practices are important specifically in SPL development: ? Domain identification and modeling, as well as commonalities and variations across product instances Separate specification and verification for platform and product requirements ? Management of integrating future requirements into the platform and products ? Identification, modeling, and management of requirement dependencies The first two practices are specific to SPL engineering. The latter two are common to software development but have much higher importance for SPLs. Issues with performing these additional activities can severely affect the product line’s long-term success. During the investigation, we found that most organizations today apply organizational and procedural measures to master these challenges. The applicability of more formal requirements engineering techniques and tools appeared rather limited, partly because such techniques are not yet designed to cope with product line evelopment’s inherent complexities. The investigation determined that the following three SPL requirements engineering practices were most important to SPL success. Domain analysis and domain description. Before starting SPL development, organizations should perform a thorough domain analysis. A well-understood domain is a prerequisite for defining a suitable scope for the product line. It’s the foundation for efficiently identifying and distinguishing platform and product requirements. Among the five participants in our investigation, three explicitly modeled the product line requirements. The others used experienced architects and domain experts to develop the SPL core assets without extensive requirements elicitation. Two organizations from the first group established a continuous requirements management that maintained links between product line and product instance requirements. The three other organizations managed their core assets’ evolution using change management procedures and versioning concepts. Their business did not force them to maintain more detailed links between the requirements on core assets and product instances. The impact of architectural decisions on requirements negotiations. A stable but flexible architecture is important for SPL development. However, focusing SPL evolution too much on architectural issues will lead to shallow or even incorrect specifications. It can cause core assets to ignore important SPL requirements so that the core assets lose relevance for SPL development. Organizations can avoid this problem by establishing clear responsibilities for requirements management in addition to architectural roles. The work group participants reported that a suitable organizational tool for balancing requirements and architecture is roundtable meetings in which requirements engineers,

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