Example of DFD for Online Store (Data Flow Diagram)

Data Flow Diagram (DFD) is a methodology of graphical structural analysis and information systems design, which describes the sources external in respect to the system, recipients of data, logical functions, data flows and data stores that are accessed. DFDs allow to identify relationships between various system's components and are effectively used in business analysis and information systems analysis. They are useful for system’s high-level details modeling, to show how the input data are transformed to output results via the sequence of functional transformations. For description of DFD diagrams are uses two notations — Yourdon and Gane-Sarson, which differ in syntax. Online Store DFD example illustrates the Data Flow Diagram for online store, the interactions between Customers, Visitors, Sellers, depicts User databases and the flows of Website Information. ConceptDraw DIAGRAM enhanced with Data Flow Diagrams solution lets you to draw clear and simple example of DFD for Online Store using special libraries of predesigned DFD symbols.

Data Flow Diagram Process

Data Flow Diagram (DFD) is a hierarchy of functional processes, connected by data flows. The purpose of this presentation is to show how each process converts its inputs into outputs and to identify relationships between these processes. DFD is convenient way of modeling and construction the information processes, it step-by-step illustrates the flow of information in a process. For construction a DFD traditionally are used two different notations, which appropriate to the methods of Yourdon-Coad and Gane-Sarson. These notations slightly different from each other by graphical representation of symbols for processes, data stores, data flow, external entities. When designing a DFD it is required to decompose the system into the components (sub-systems), for explaining a complex system you may need represent numerous levels. The Data Flow Diagrams solution from ConceptDraw Solution Park contains numerous predesigned DFD symbols for both notations, which help easy and effectively design professional-looking Data Flow Diagrams (DFDs) and DFD Process Diagrams.

Data Flow Diagram Model

Data Flow Diagram (DFD) is a technique of graphical structural analysis, describing the sources external to the system, recipients of data, also logical functions, data flows and data stores that are accessed. The DFD's goal is to show how each process converts its inputs into the outputs and to identify relationships between these processes, at this make the system's description clear and understandable at every level of detail. Historically happened that for describing Data Flow Diagrams are used two notations - Yourdon and Gane-Sarson that differ each from other by graphical representation of symbols. The DFD model, like most other structural models is a hierarchical model. Each process can be subjected to decomposition on the structural components, the relationships between which in the same notation can be shown on a separate diagram. Typically, several DFD models are built when modeling the system. ConceptDraw DIAGRAM software enhanced with Data Flow Diagrams solution ideally suits for creation DFD models and professional drawing Data Flow Diagrams.

Data Flow Diagram

Data Flow Diagram (DFD) is the part of the Structured Systems Analysis and Design Methodology (SSADM), which is intended for information systems projection and analysis. Data Flow Diagrams allow graphically represent the data flows in information system and analyze the data processing during the structural projection. This type of diagrams lets visually show a work of information system and results of this work, it is often used in connection with human processes and can be displayed as Workflow diagram. Data Flow Diagram visualizes processes and functions, external entities, data depositories, and data flows connecting these elements and indicating direction and data character. Each of these elements used for DFD has its own graphical notation. There are two notations to draw DFDs - Yourdon & Coad and Gane & Sarson. ConceptDraw DIAGRAM extended with Data Flow Diagrams (DFD) solution from Software Developmant area is ideal for designing professional looking DFDs, which can be then easily exported in various formats.

Gane Sarson Diagram

The Gane-Sarson methodology uses the graphical techniques for building the logical models for the systems. It is helpful for analysts and designers to make common and clear picture of the system, to depict all its processes and how they transform the data. The Gane-Sarson methodology lets represent all this information in a way understandable for the users and other interested people, and gives the possibility to see instantly how the system's parts serve together to meet their needs. This methodology supposes the building of a system top-down. First you need create an overall system data flow, then determine the details of the data structures, the process logic and design the modular structures. ConceptDraw DIAGRAM diagramming and vector drawing software offers the Data Flow Diagrams solution with Gane-Sarson Notation library rich for the specific symbols of the Gane-Sarson notation. All they are vector and fully ready-to-use for drawing the Data Flow Diagrams, which will be then successfully used in presentations, websites, and various business documents.

Data Flow Diagram Symbols. DFD Library

Data Flow Diagrams graphically represent the information transfers and process steps of a system. They visually depict how data are processed by a system in terms of inputs and outputs, how occurs the input in a system, how the data flow through an information system and where they are stored, and how occurs output from the system. DFDs give the overview of the system and models the processes aspects, they are maintained with other methods of structured systems analysis. The main goal of DFDs is achievement of understanding between developers and users. For their construction are used two notations - Gane-Sarson and Yourdon, each of them uses its own set of symbols. Data Flow Diagrams solution from Software Development area extends the ConceptDraw DIAGRAM software with templates, samples, and predesigned libraries of data flow diagram symbols for both notations, allowing you easy design the process-oriented and data-oriented models, draw the Data Flow Diagrams, Data Flowcharts, Data Process Diagrams, Information Flow Diagrams, Structured Analysis Diagrams, etc.

Taxi Service Data Flow Diagram DFD Example

This sample shows the Data Flow Diagram of the Taxi Service and interactions between the Clients, Operators and Divers, as well as Orders and Reports databases.

Data Flow Diagram Software

Data Flow Diagrams (DFDs) are successfully used when studying the business processes or systems that involve the transfer of data. They are a visual way to represent the data processing, to model and visualize the flow of data through a computer system and functional requirements for a designed system. They are the good business modeling tool to describe the business events and interactions, the physical systems involving the storage and transfer of data. ConceptDraw DIAGRAM supplied with Data Flow Diagrams solution from Software Development area of ConceptDraw Solution Park is a modern and powerful data flow diagram software. This solution offers large set of predesigned DFD vector objects, grouped to three libraries: Data Flow Diagrams, Gane-Sarson Notation, and Yourdon and Coad Notation. All they and also collection of DFD samples and built-in templates make a good base for ConceptDraw DIAGRAM users, providing them all conditions for easy creation the Data Flow Diagrams and Data Flow Models of any complexity.

Structured Systems Analysis and Design Method (SSADM) with ConceptDraw DIAGRAM

Structured Systems Analysis and Design Method (abbr. SSADM) is a method developed in Great Britain and accepted in 1993 as a national standard for information systems development and analysis. SSADM is based on Data Flow Diagrams and is characterized with presence of clear sequence of steps at projecting, analysis, and documenting of information system. It involves 6 main stages: analysis of existing system or estimation of practicability, requirements definition, determination of technical requirements and equipment cost, development of logical data model, projecting of logical requirements and specification them, physical projecting. Each of them is also divided into several steps defining the tasks that should be fulfilled at a given stage. The most important SSADM elements are flows modeling with help of DFD, data logic modeling with help of LDS (Logical Data Structure) and description of entities behavior. Applying of SSADM is easy with ConceptDraw DIAGRAM diagramming and vector drawing software and Data Flow Diagram solution.

DFD Library — Design elements

Data Flow Diagrams (DFD) solution from the Software Development area of ConceptDraw Solution Park provides plenty of predesigned templates, samples and DFD vector design elements proposed by three DFD libraries. These DFD library objects are designed to help you effectively model the data flows and functional requirements for the business processes or systems, to design the Process-oriented models or Data-oriented models, Data flowcharts and Data process diagrams, Structured analysis diagrams and Information flow diagrams. There are two different notations used to draw the Data Flow Diagrams (Yourdon & Coad and Gane & Sarson). These notations define the different visual representations for the processes, data stores, data flows, and external entities. ConceptDraw DIAGRAM software provides you with possibility of designing professional-looking Data Flow Diagrams, DFD Models, Data Flow Process Diagrams using any of these notations. Simply drag the predesigned DFD flowchart symbols from the appropriate library and connect by arrows depicting the data flow from one step to another.