序列图(SD)和系统序列图(SSD)之间的区别? [英] Difference between Sequence Diagram (SD) and a System Sequence Diagram (SSD)?

问题描述

我正在为一个研究生班设计一个项目，但是仍然无法解决问题.

I'm working on a project for a grad class and still having trouble wrapping my head around them.

序列图(SD)和系统序列图(SSD)有什么区别?

在进行系统开发项目时，应按什么顺序开发它们?

And in what order should they be developed when working on a systems development project?

推荐答案

一个系统顺序图可视化用例，而序列图可视化类的方法.

A System sequence diagram visualizes a use case, while a sequence diagram visualizes a method of a class.

系统顺序图中参与(交换消息)的元素是参与者和系统.根据系统的不同，这些元素交换的消息可以是任何类型(从Web服务调用到人工输入的数据).

The elements participating (exchanging messages) in a system sequence diagram are Actors and Systems. The messages exchanged by these elements could be any type depending on the systems (from web service calls to data input from a human).

参与序列图的元素是对象(各种类的实例).这些元素交换的消息是方法调用.

The elements participating in a sequence diagram are objects (instances of various classes). The messages exchanged by these elements are method invocations.

首先，您将分析并记录用例.每个用例都描述了所需的主要业务任务.系统用例图是此活动的一部分.

First you would analyze and document the use cases. Each use case describes a main business task required. The system use case diagram is part of this activity.

稍后，您将设计每个子系统，即参与系统用例图的每个元素.您绘制一个或多个类图，描述参与该解决方案的类.然后，您将为最重要(或难以理解)的方法绘制序列图.

Later you come to design each subsystem, namely each element participating in the system use case diagram. You draw one or more class diagrams depicting the classes participating to the solution. Then you would draw a sequence diagram for the most important (or difficult to understand) methods.

可以在敏捷建模网站中找到一些示例.

Some examples can be found in the agile modelling site.

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