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A data flow diagram (DFD) is a graphical representation of the "flow" of data through an information system, modeling its process aspects. DFDs can also be used for the visualization of data processing (structured design).

8 votes

What is a good diagrammatic way to represent async event communication between two systems?

The UML sequence diagram is well adapted to represent an interaction between several objects (or components or, why not,systems). It has semantic to make the difference between synchronous and asynchr …
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5 votes
Accepted

In a Data Flow Diagram, can 2 entities use the same process (with the same incoming data flow)?

According to Yourdon & Demarco who’s notation you use, each process should be uniquely numbered and appear in only one of the data flow decomposition diagram. Your second alternative would therefore b …
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4 votes
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A Case Study Dataflow Diagram

1. Data flows from and to the data store: The Gane & Sarson DFD notation, which used in this diagram, tells that there is indeed a flow of data corresponding to Product Item from the process Browse Ca …
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3 votes
Accepted

Data Flow Diagram for patient information system for a hospital

You seem to be mislead by the name of the process Maintain patient info, which suggests that patient records are created there. If we forget about the assumption and look at the flows involving the …
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3 votes

Do data stores appears in Level 1 DFD?

There is indeed an ambiguity whether the DFD level count start as 0 with the context diagram (example here), or the overview diagram below the context diagram (example in this article). The context di …
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2 votes

Drawing UML activity diagram for Statistics feature

Just looking at the diagram without looking at the code: the text over edges outgoing from a decision node should always be [ between bracket ] the decision making cascade with several [ none of …
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2 votes
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Refining DFD of an RPG

What do you expect from the diagram ? To be very provocative: What does your diagram tell you that you do not already know ? Isn't this diagram confusing since Urdu Boli the game and everybody will …
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2 votes
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How to represent a duplicate data store in a data flow diagram (DFD) in the Yourdon DeMarco ...

Yourdon/Demarco avoids duplication where possible. For example, processes are unique, and data-flow names are supposed to be unique. They do not mention uniqueness for data-stores nor external entitie …
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2 votes

Could conditions be used with Data Flow Diagrams?

Dataflow diagrams are not as powerful and standardized as UML activity diagrams; there is no notation for conditions. The usual practice would be to have three outgoing dataflows, that each describe t …
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0 votes

How to show data flow between entities in a data flow diagram when input data and output dat...

Typical Dataflow diagrams (DFD) represent distinct flow of data between two functions as a distinct edge, regardless of the type of data: +----------+ +--------------+ …
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0 votes

Are there still advantages of the data-flow diagram in a world of SysML and UML?

Structured analysis Structured analysis, pioneered by Tom DeMarco (Yourdon Inc.) & Larry Constantine, or Chris Gane & Trish Sarson, and a couple of other methodologists, dates back to the 1970s. Three …
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