数据流程图和流程图有什么区别？
我想知道为什么我们使用数据流程图而不是流程图。
I want to know why we use Data Flow Diagrams instead of flow charts.
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我想知道为什么我们使用数据流程图而不是流程图。
I want to know why we use Data Flow Diagrams instead of flow charts.
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流程图描述了程序（参见旧的 Fortran 流程图 - 当然，谷歌上有一些）。
数据流图决定了数据的流动，例如子程序之间或不同程序之间的数据流。
Flow chart describes the program (see old fortran flow charts - surely, there are some floating around on google).
Data flow diagram determines the flow of data, for example, between subroutines, or between different programs.
尽管我对 DFD 图的经验有限，但我可以告诉您，DFD 向您展示了数据如何在各个模块之间移动（流动）。 此外，DFD 可以划分为多个级别，即在初始级别中，您将系统（例如，电影租赁系统）视为一个整体（称为上下文级别）。 该级别可以分解为另一个级别，其中包含活动（例如，租借电影、归还电影）以及数据如何流入这些活动（可以是名称、天数等）。 现在，您可以为每个活动创建一个子级别，详细说明这些活动的许多任务或场景。 等等，等等。 请记住，数据总是在级别之间传递。
至于流程图，请记住流程图描述了一种算法！
Although my experience with DFD diagrams is limited I can tell you that a DFD shows you how the data moves (flows) between the various modules. Furthermore a DFD can be partitioned in levels, that is in the Initial Level you see the system (say, a System to Rent a Movie) as a whole (called the Context Level). That level could be broken down into another Level that contains activities (say, rent a movie, return a movie) and how the data flows into those activities (could be a name, number of days, whatever). Now you can make a sublevel for each activity detailing the many tasks or scenarios of those activities. And so on, so forth. Remember that the data is always passing between levels.
Now as for the flowchart just remember that a flowchart describes an algorithm!
看看这个网站
http://yourdon.com/strucanalysis/ wiki/index.php?title=Chapter_9#The_Flow
它确实帮助你理解什么是 DFD
have a look to this site
http://yourdon.com/strucanalysis/wiki/index.php?title=Chapter_9#The_Flow
its really help u to understand what is DFD
在上面的答案之间已经进行了解释，但我会尝试稍微扩展一下......
关于一杯茶的观点是一个很好的观点。 流程图与任务的物理方面有关，因此用于表示当前的事物现状。 这对于培养对情况/沟通/培训等的理解很有用。您可能会在工作场所遇到过这些，当然，如果他们采用了 ISO9000 标准。
数据流程图是与一项活动的逻辑方面有关，因此，一杯茶的比喻是一个很好的比喻。 如果您将数据流程图与过程流结合使用，您的数据流将仅涉及与过程相关的数据/信息流，而不考虑物理方面。 如果您想知道为什么这会很有用，那么这是因为数据流程图使我们能够摆脱“现状”的情况，并看到它可能/将会是什么。 这两种建模方法在结构化分析和设计中很常见，通常由系统/业务分析师用作业务流程改进/重新设计的一部分。
Between the above answers its been explained but I will try to expand slightly...
The point about the cup of tea is a good one. A flow chart is concerned with the physical aspects of a task and as such is used to represent something as it is currently. This is useful in developing understanding about a situation/communication/training etc etc..You will likley have come across these in your work places, certainly if they have adopted the ISO9000 standards.
A data flow diagram is concerned with the logical aspects of an activity so again the cup of tea analogy is a good one. If you use a data flow diagram in conjunction with a process flow your data flow would only be concerned with the flow of data/information regarding a process, to the exclusion of the physical aspects. If you wonder why that would be useful then its because data flow diagrams allow us to move from the 'as it is' situation and see it that something as it could/will be. These two modelling approaches are common in structured analysis and design and typically used by systems/business analysts as part of business process improvement/re-engineering.
数据流图：表示系统功能分解的建模符号。
流程图：程序的逐步流程。
Data flow diagram: A modeling notation that represents a functional decomposition of a system.
Flow chart: Step by step flow of a programe.
数据流程图
正式的结构化分析方法采用数据流图（DFD）来协助功能分解过程。 我从 DeMarco [7] 那里学到了结构化分析技术，这些技术代表了当前的惯例。 总而言之，DFD 由四个部分组成：
Data Flow Diagrams
The formal, structured analysis approach employs the data-flow diagram (DFD) to assist in the functional decomposition process. I learned structured analysis techniques from DeMarco [7], and those techniques are representative of present conventions. To summarize, DFD's are comprised of four components:
流程图详细说明了要遵循的流程。 DFD 详细描述了系统中的数据流。
在流程图中，箭头表示元素之间的控制（而不是数据）转移，元素是指令或决策（或I/O等）。
在 DFD 中，箭头实际上是元素之间的数据传输，元素本身就是系统的一部分。
维基百科此处有一篇关于 DFD 的好文章。
A flow chart details the processes to follow. A DFD details the flow of data through a system.
In a flow chart, the arrows represent transfer of control (not data) between elements and the elements are instructions or decision (or I/O, etc).
In a DFD, the arrows are actually data transfer between the elements, which are themselves parts of a system.
Wikipedia has a good article on DFDs here.
你应该使用任何你喜欢的东西。 图表只是一个工具。 使用最适合您和您的问题的工具。 我通常只使用方框、箭头、曲线、圆圈、小简笔画以及其他我认为能让观众明白要点的东西。 简而言之，即使您使用标准图表标准也没关系。 人们通常很善于理解图片。
You should use whatever you like. The diagram is just a tool. Use whatever tool fits you and your problem best. I usually just use boxes and arrows and squiggles and circles and little stick figures and whatever else I think gets the point across to the viewer. In short it doesn't matter if you even use a standard diagraming standard. People are usually pretty good at understanding pictures.
数据流程图显示系统中不同实体和数据存储之间的数据流，而流程图显示执行任务所涉及的步骤。 从某种意义上说，数据流程图提供了系统的非常高级别的视图，而流程图是较低级别的视图（基本上显示算法）。
使用数据流图还是流程图取决于弄清楚您要显示的内容。
Data flow diagram shows the flow of data between the different entities and datastores in a system while a flow chart shows the steps involved to carried out a task. In a sense, data flow diagram provides a very high level view of the system, while a flow chart is a lower level view (basically showing the algorithm).
Whether you use data flow diagram or flow charts depends on figuring out what is it that you are trying to show.
数据流图（DFD）和流程图（FC）之间的区别在于，数据流图通常描述系统内的数据流，而流程图通常描述业务流程的详细逻辑。
The difference between a data flow diagram (DFD) and a flow chart (FC) are that a data flow diagram typically describes the data flow within a system and the flow chart usually describes the detailed logic of a business process.
数据流和流程图在过程、流程和时间上有所不同。
流程
a.) 在 DFD 上，进程可以并行（同时）运行。
b.) 在流程图上，流程一次执行一个。
流量
a.) DFD 显示通过系统的数据流
b.) 流程图显示控制流（控制顺序和转移）
时序
a.) DFD 上的进程可以有显着不同的时间安排（每日、每周、按需）
b.)
流程图上的流程是具有一致计时的单个程序的一部分
Data Flow and Flow Chart differ in processes, flow, and timing.
Processes
a.) On DFDs, processes can operate in parallel (at-the-same-time).
b.) On flowcharts, processes execute one at a time.
Flow
a.) DFDs show the flow of data through a system
b.) Flowcharts show the flow of control (sequence and transfer of control)
Timing
a.) Processes on a DFD can have dramatically different timing (daily, weekly, on demand)
b.)
Processes on flowcharts are part of a single program with consistent timing
DFD 显示数据如何在系统中移动，流程图更接近系统执行的操作。
在经典的泡一杯茶的示例中， DFD 将显示水、茶、牛奶、糖的去向，而流程图则显示整个过程。
A DFD shows how the data moves through a system, a flowchart is closer to the operations that system does.
In the classic make a cup of tea example, a DFD would show where the water, tea, milk, sugar were going, whereas the flowchart shows the process.
其他答案已经概述了每件事的基础知识。 在更高的层面上，流程图是一种设计级工具，而 DFD 更多的是分析。
DFD 有一些不错的功能。 由于它们显示了数据流，因此当以这种方式绘制图表时，有些事情会变得更加明显：一些数据仅由少数例程使用，一些例程仅使用某些数据位，一些例程涉及所有内容。 预先了解这一点有助于组织、重组和规划。
接下来值得探索的是事件响应图，它基本上是一个 DFD，仅显示处理“事件”所需的流程和数据，这意味着外部触发的事件（客户付款等）。
Other answers have gone over the basics of what each thing is. At the higher level, a flowchart is a design level tool, while DFDs are more analysis.
DFDs have some nice features. Since they show the flow of data, some things become more obvious when charted this way: some data is only used by a few routines, some routines use only some bits of data, some routines touch everything. Seeing that up front helps organize, restructuring, and planning.
A follow-on worth exploring is the Event-Response Diagram, which is basically a DFD only showing process and data needed to process an "event", meaning something triggered externally (customer makes payment, etc.).
数据流图是函数关系，包括输入值和输出值
和存储的内部数据。
流程图是一种包含输入和输出值的过程关系。
A Data Flow Diagram is functional relationship which includes input values and output values
and internal data stored.
A Flow Chart is a process relationship which includes input and output values.