The V model P2.1

杨世强 · 发表于 2007-9-20 18:51:08

<

class=MsoNormal style="MARGIN: 0cm 0cm 0pt">The V model is commonly used to identify the relationship between the development and testing phases, and to ensure that appropriate quality assurance and testing takes place throughout the project lifecycle. See diagram.<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com

ffice

ffice" /><o:p></o:p>
<

class=MsoNormal style="MARGIN: 0cm 0cm 0pt"><o:p> </o:p>
<

class=MsoNormal style="MARGIN: 0cm 0cm 0pt">In this diagram, the term “requirements specification” is used to define the agreed business requirements of the organisation. 如，系统能做什么。<o:p></o:p>
<

class=MsoNormal style="MARGIN: 0cm 0cm 0pt"><o:p> </o:p>
<

class=MsoNormal style="MARGIN: 0cm 0cm 0pt">These business requirements form the basis of user acceptance testing. Requirements are developed in detail in the “functional specification” stage, in which diagrams such as flowcharts, entity-relationship models diagrams are used to model the requirements. These models also provide the basis of the test cases subsequently used in system testing. <o:p></o:p>
<

class=MsoNormal style="MARGIN: 0cm 0cm 0pt"><o:p> </o:p>
<

class=MsoNormal style="MARGIN: 0cm 0cm 0pt">A key issue in this stage is the “testability” of the functional specification. The project is not allowed to progress to “system design” until test cases have been derived from the specification.<o:p></o:p>
<

class=MsoNormal style="MARGIN: 0cm 0cm 0pt"><o:p> </o:p>
<

class=MsoNormal style="MARGIN: 0cm 0cm 0pt">System design is concerned with the design of computer system that will deliver the requirements defined in the functional specification. It is a technical stage of development, usually performed by senior programmers, architects and designers. If the functional specification states what is required, then the system design will define how it will be delivered. System design forms the basis for integration testing (sometimes called integration testing in the small, link testing, or assembly testing).<o:p></o:p>
<

class=MsoNormal style="MARGIN: 0cm 0cm 0pt"><o:p> </o:p>
Finally, individual programs or modules are specified in “unit design” and these form the basis of the test cases of unit testing. Unit testing is sometimes called “component testing” or “program testing”. The V model suggests that this testing should be performed formally from the outputs of unit design, in additional to any ad hoc testing performed by programmers in the program coding stage.<o:p></o:p>
<o:p> </o:p>
The V model has a number of benefits: 1. system development projects usually have a test approach, or test strategy document, which defines how testing will be performed throughout the lifecycle of the project. The V model provides a consistent basis and standard for part of that strategy. 2. The V model suggests that testing (quality assurance) should be considered early on in the life of a project. Evidences suggest that the earlier a fault is found, the cheaper it is to fix. 3. The V model provides a basis for defining who is responsible for performing the testing at each stage. Here are some typical responsibilities: <o:p></o:p>
-         acceptance testing performed by users<o:p></o:p>
-         system testing performed by system testers<o:p></o:p>
-         integration testing performed by program team leaders<o:p></o:p>
-         unit testing performed by programmers<o:p></o:p>
<o:p> </o:p>
Therefore, the V model is very useful in planning and executing information system development. It should assist the delivery of software that reliably fulfils its defined requirements. <o:p></o:p>

杨世强 · 发表于 2007-9-20 19:37:05

谢谢！分享！

shui2001 · 发表于 2007-9-21 22:35:25

2.1已经不在考试大纲里了~~

杨世强 · 发表于 2007-9-23 07:55:01

哦，对哦！都忘了，呵呵

账号		自动登录	找回密码
密码			立即注册

The V model P2.1

英俊潇洒