Chapter 6 Software Engineering 6.1.1 The Cycle as a whole The software life cycle is shown in Figure 6-1. This figure represents the fact that once software is developed, it enters a cycle of being used and modified that continues for the rest of the software's life. Such a pattern is common for many manufactured products as well. The difference is that, in the case of other products, the modification phase is more accurately called a repair or maintenance phase because other products tend to move from being used to being modified as their parts become worn. 在图6-1中展示了软件的生命周期。这个图说明了一个事实:一且软件开发 完成,它就进入了使用和修改的循环,并且这个循环将在软件生命期的剩 余时间中不断进行。这样的模式对机器制造的产品而言也是很普通的。不 同之处在于,对于其他产品,软件工程中的修改阶段要被更精确地称作修 理或者维护阶段,因为其他产品由于部件的磨损会有从使用到修改的过程。 计算机专业英语 6-6
Chapter 6 Software Engineering 计算机专业英语 6-6 6.1.1 The Cycle as a Whole The software life cycle is shown in Figure 6-1. This figure represents the fact that once software is developed, it enters a cycle of being used and modified that continues for the rest of the software's life. Such a pattern is common for many manufactured products as well. The difference is that, in the case of other products, the modification phase is more accurately called a repair or maintenance phase because other products tend to move from being used to being modified as their parts become worn. 在图6-1中展示了软件的生命周期。这个图说明了一个事实：一旦软件开发 完成，它就进入了使用和修改的循环，并且这个循环将在软件生命期的剩 余时间中不断进行。这样的模式对机器制造的产品而言也是很普通的。不 同之处在于，对于其他产品，软件工程中的修改阶段要被更精确地称作修 理或者维护阶段，因为其他产品由于部件的磨损会有从使用到修改的过程
Chapter 6 Software Engineering 6.1.1 The Cycle as a whole Software. on the other hand does not wear out. Instead software moves into the modification phase because errors are discovered, because changes in the softwares application occur that require corresponding changes in the software, or because changes made during a previous modification are found to induce problems elsewhere in the software For example, changes in tax laws may require modifications to payroll programs that calculate withholding taxes, and all too often these changes may have adverse effects in other areas of the program that may not be discovered until some time later. 当然,软件不存在磨损的问题。但是,软件进入修改阶段或者是因为错误 被发现,或者是因为要在软件的应用程序中进行修改从而修改了软件,或 者是因为先前的改变又引起了软件其他地方出现了新的问题。例如,税务 法案的改变导致对计算扣税的工资程序进行修改,而太频繁的修改则会在 软件的其他地方引起反面的作用,而这些是不会被立即发现的。 计算机专业英语
Chapter 6 Software Engineering 计算机专业英语 6-7 6.1.1 The Cycle as a Whole Software, on the other hand, does not wear out. Instead, software moves into the modification phase because errors are discovered, because changes in the software's application occur that require corresponding changes in the software, or because changes made during a previous modification are found to induce problems elsewhere in the software. For example, changes in tax laws may require modifications to payroll programs that calculate withholding taxes, and all too often these changes may have adverse effects in other areas of the program that may not be discovered until some time later. 当然，软件不存在磨损的问题。但是，软件进入修改阶段或者是因为错误 被发现，或者是因为要在软件的应用程序中进行修改从而修改了软件，或 者是因为先前的改变又引起了软件其他地方出现了新的问题。例如，税务 法案的改变导致对计算扣税的工资程序进行修改，而太频繁的修改则会在 软件的其他地方引起反面的作用，而这些是不会被立即发现的
Chapter 6 Software Engineering 6.1.1 The Cycle as a whole Regardless of why software enters the modification phase the process requires that a person(often not the original author) study the underlying program and its documentation until the program, or at least the pertinent part of the program, is understood. Otherwise, any modification could introduce more problems than it solves. Acquiring this understanding can be a difficult task even when the software is well-designed and documented. In fact, it is often within this phase that a piece of software is finally discarded under the pretense(too often true)that it is easier to develop a new system from scratch than to modify the existing package successfully 不管因为什么原因软件进入了修改阶段,这个过程需要人们(通常不是原 始的作者)研究程序及其文档,直到程序或者至少是相关部分的程序能够 被理解。否则,任何的修改将导致比它所解决问题还要更多的问题出现 即使软件有优秀的设计和齐备的文档,理解也是一个很困难的工作。事实 上,常常是在这个阶段,一个有用的软件片段最终就被放弃了(常常是这 样),而开发一个新的系统比成功地修改现有软件更容易。 计算机专业英语 68
Chapter 6 Software Engineering 计算机专业英语 6-8 6.1.1 The Cycle as a Whole Regardless of why software enters the modification phase, the process requires that a person (often not the original author) study the underlying program and its documentation until the program, or at least the pertinent part of the program, is understood. Otherwise, any modification could introduce more problems than it solves. Acquiring this understanding can be a difficult task even when the software is well-designed and documented. In fact, it is often within this phase that a piece of software is finally discarded under the pretense (too often true) that it is easier to develop a new system from scratch than to modify the existing package successfully 不管因为什么原因软件进入了修改阶段，这个过程需要人们（通常不是原 始的作者）研究程序及其文档，直到程序或者至少是相关部分的程序能够 被理解。否则，任何的修改将导致比它所解决问题还要更多的问题出现。 即使软件有优秀的设计和齐备的文档，理解也是一个很困难的工作。事实 上，常常是在这个阶段，一个有用的软件片段最终就被放弃了（常常是这 样），而开发一个新的系统比成功地修改现有软件更容易
Chapter 6 Software Engineering 6.1.1 The Cycle as a whole Experience has shown that a little effort during the development of software can make a tremendous dfference when modifications in the software are required. 经验告诉我们软件开发过程中的一丁点付出,会在软件需要 修改的时候带来巨大的不同。 In turn most of the research in software engineering focuses on the development stage of the software life cycle, with the goal being te take advantage of this effort-versus-benefit leverages 反过来,大多数软件工程的研究都集中于软件生命周期的开发 阶段,它们的目标是要利用这个付出与收益的杠杆作用 计算机专业英语
Chapter 6 Software Engineering 计算机专业英语 6-9 6.1.1 The Cycle as a Whole Experience has shown that a little effort during the development of software can make a tremendous difference when modifications in the software are required. 经验告诉我们,软件开发过程中的一丁点付出，会在软件需要 修改的时候带来巨大的不同。 In turn, most of the research in software engineering focuses on the development stage of the software life cycle, with the goal being to take advantage of this effort-versus-benefit leverage. 反过来，大多数软件工程的研究都集中于软件生命周期的开发 阶段，它们的目标是要利用这个付出与收益的杠杆作用
Chapter 6 Software Engineering 6.1.1 The Cycle as a whole The Traditional Development Phase The stages within the development phase of the software life cycle are analysis, design, implementation, and testing (Figure 6-2). Analysis Hgn Implementati Testing 软件生命周期的开发阶段包括分析、设计、实现与测试等步骤(如图6-2所 计算机专业英语 6-10
Chapter 6 Software Engineering 计算机专业英语 6-10 6.1.1 The Cycle as a Whole The Traditional Development Phase The stages within the development phase of the software life cycle are analysis, design, implementation, and testing (Figure 6-2). 软件生命周期的开发阶段包括分析、设计、实现与测试等步骤（如图6-2所 示）。 Analysis Design Implementation Testing