Data Flow Diagram
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Data Flow Diagram (DFD) is the part of the SSADM method (Structured Systems Analysis and Design Methodology), intended for analysis and information systems projection. Data Flow Diagrams are intended for graphical representation of data flows in the information system and for analysis of data processing during the structural projection. By means of data flow diagrams it is possible to show visually the work of the information system and results of this work. Data Flow Diagram visualizes processes, data depositories and external entities in information systems and data flows connecting these elements. Data Flow Diagram consists of following components:
This variant of presentation of Data Flow Diagram objects got the name of Yourdon – de Marco notation.
Objects of Data Flow Diagrams are interpreted in the following way:
Every diagram object should have a name. Each data flow is denoted with indication of transferred data and with the possibility of indication of the format of these data. Data Flow Diagram should not involve more than 10 objects, excluding arrows, representing data flows. In case of more complicated system the totality of several objects (as a rule, processes) is united and represented on the diagram in the form of one object. This complicated compound object is presented in the form of a separate flows diagram. Each component has a number, at this, diagrams illustrating compound objects are numerated starting from the number of an object which they describe. For example components of the diagram of the description of an object with number 5 will be numerated 5.1, 5.2 etc. Generally Process Flow Diagram depicts just the major equipment without details. For clearness there is a possibility to duplicate notations of used data depositories and external entities. Processes can’t be duplicated. For example if one the same data depository is used in several different processes it is better to duplicate it on the diagram but not to create several intricate data flow arrows from one object to several processes. This concerns external entities as well. Duplicates of data depositories are marked with the double line from the left side, external entities duplicates - with the asterisk. Data flows on the diagram can ramify and merge that implies branching or confluence of data in the information system. |
Example 1. Data Flow Diagram
Thus the information system is represented by a planner in the form of the high level DFD in which objects are worked out in details by diagrams of the lower level with the preset level of detailed elaboration. There is also another way of looking at which all events in the system are described at once and each event is represented in the form of process transforming data flows, further these subruns are grouped for getting diagrams of the higher level.
Data Flow Diagrams Solution the best Data Flow Diagram software:
- You don't need to be an artist to draw professional looking diagrams in a few minutes.
- Large quantity of ready-to-use vector objects makes your drawing diagrams quick and easy.
- Great number of predesigned templates and samples give you the good start for your own workflow diagram or process flow diagram.
- ConceptDraw DIAGRAM provides you the possibility to use the grid, rules and guides. You can easily rotate, group, align, arrange the objects, use different fonts and colors to make your organizational workflow diagram exceptionally looking.
- All ConceptDraw DIAGRAM documents are vector graphic files and are available for reviewing, modifying, and converting to a variety of formats: image, HTML, PDF file, MS PowerPoint Presentation, Adobe Flash, MS Visio.
- Using ConceptDraw STORE you can navigate through ConceptDraw Solution Park, managing downloads and updates. You can access libraries, templates and samples directly from the ConceptDraw STORE.
- If you have any questions, our free of charge support is always ready to come to your aid.
TEN RELATED HOW TO's:
Data Flow Diagram Software →
When studying a business process or system that involves the transfer of data, it is common to use a Data Flow Diagram (DFD) to visualize how that data are processed. Being initially used exclusively in regards to the flow of data through a computer system, now DFDs are employed as the business modeling tools, for describing business events and interactions, or physical systems involving data storage and transfer. ConceptDraw DIAGRAM is a powerful Data Flow Diagram software thanks to the Data Flow Diagrams solution from the Software Development area of ConceptDraw Solution Park.
Data Flow Diagram Process →
When you are a beginner in software development, you make a lot of mistakes. Developing logical models, or data flow diagrams is a way to see the the whole project and all the processes clearly. And some novices, unfortunately for them, miss modeling stage at the beginning of project life cycle, and get into troubles as the project grows. This image represents the data flow diagram applying symbols of Yourdon and Coad notation. This DFD depicts the data flow inside an organization department deals with receivables. The icons of standard Yourdon and Coad notation provides possibility to draw professional looking and well- readable DFD for business documentation. This data flow diagram was designed with the help of ConceptDraw DIAGRAM and its Data Flow Diagrams solution. The solution delivers three vector graphic libraries including elements of Yourdon and Coad and Gane-Sarson notations.
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Process Flow Chart →
A Process Flow Chart is a type of flowchart which is mostly used in industrial, chemical and process engineering for illustrating high-level processes, major plant processes and not shows minor details. ConceptDraw DIAGRAM diagramming and vector drawing software extended with Flowcharts Solution from the "Diagrams" Area of ConceptDraw Solution Park is the best way to create Process Flow Chart and other types of flowcharts.
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Data Flow Diagram Examples →
Data flow diagrams are the graphical tool, used in the visualization of data flow of some data processing systems. It is the valuable process modeling tool. Also designing DFD is the important component of the initial part of any information system development project. The standard symbols are used to represent the interaction of a system components and how various kinds of components influence on data flow. The ConceptDraw Data Flow Diagrams solution is design to assist professional software engineers in making DFDs according to Gane and Sarson, and Yourdon and Coad notations. Do you imagine yourself as a successful IT specialist? To your mind, they all use data flow diagram examples to learn and to get inspired. Aren’t you still with us?
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