To derive alternative flows, use activity diagrams.
为得到可选流程，使用活动图5。
Besides the basic flow, there are many alternative flows.
除了基本流程以外，还有许多可选流程。
Numerous alternative flows, including exceptions and errors, may also exist.
大量的可选择流程，包括例外情况和错误，也可能存在。
There is one scenario per alternative flow plus one scenario for each combination of alternative flows.
每一个可选流程都有一个场景，并且每个结合的可选流程都有一个场景。
There is one scenario per alternative flow plus one scenario for each combination of alternative flows.
每个可选流加上一个可供选择的流程的组合仍然是一个流程。
Figure 12 shows all the scenarios: 21 scenarios derived from different combinations of alternative flows.
图12显示了全部的场景：从不同的可选流程合并中产生21个场景。
Scenario 1: Modeling branching behavior discusses the branching and joining of parallel and alternative flows.
场景1：分支行为建模讨论了如何对并行流和可选流进行分支和联接。
The basic flow is a straight line down, while alternative flows are usually the loops going either back or forth.
基本流程是一条向下的直线，然而可选流程可以是向前或向后的循环线。
In general, automated activities correspond to the steps in the use case flows (main scenario and alternative flows).
通常，自动化活动与用例流(主场景和备选流)中的步骤对应。
These documents provide detailed guidance on how the application is intended to operate, including its core and alternative flows.
这些文档提供了关于应用软件如何进行操作的详细指南，包括其核心和可选工作流。
Alternative flows cannot guarantee the availability of inputs for an activity that expects these inputs from several alternative branches.
对于某个期待从几个分支获得输入的活动而言，可选流无法保证这些输入的可用性。
Usually it is wise to select a basic flow, one scenario covering each alternative flow, and some reasonable combinations of alternative flows.
通常，明智的做法是选择一个基础流程，一个覆盖了每一个可选流程的场景，以及一些合理的可选流程的结合。
For example, an interface to an external system that involves complex interaction may require several steps or alternative flows to be defined.
例如，涉及到复杂交付的外部系统的接口可能要求定义多个步骤或备选流。
The options that have the bar after them throw the user out of the basic flow: they represent some errors that are described in alternative flows.
后面有妨碍的选项把用户从基本流程中抛离出去：它们表示在可选流程中描述的一些错误。
The basic flow and the alternative flows are clear and are understandable by the development and test teams, and have received approval from the end users.
基本流和可选流对于开发和测试团队是清晰的和可以理解的，并且已经收到了最终用户的正式批准。
There are definitely more scenarios than alternative flows, because there's one for A1, another one for A2, and one scenario which will be a combination of these two.
显然，这里场景多于可选流程，因为一个场景用于A1，另一个场景用于A2，还有一个场景用于这两个的结合。
Then determine whether these flows occur as parallel or alternative branches in the process model.
然后再确定这些流在流程模型中是否是以并行或可选分支的形式出现的。
In the meantime, they are using alternative policies to try to slow their economies and foreign capital flows, with the occasional small rate rise.
与此同时，它们正在利用其他政策减缓经济增长和外资流入速度，只是偶尔进行小幅加息。
In the meantime, they are using alternative policies to try to slow their economies and foreign capital flows, with the occasional small rate rise.
与此同时，它们正在利用其他政策减缓经济增长和外资流入速度，只是偶尔进行小幅加息。
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