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.

Basic Flowchart Symbols and Meaning

Flowcharts are the best for visually representation the business processes and the flow of a custom-order process through various departments within an organization. ConceptDraw DIAGRAM diagramming and vector drawing software extended with Flowcharts solution offers the full set of predesigned basic flowchart symbols which are gathered at two libraries: Flowchart and Flowcharts Rapid Draw. Among them are: process, terminator, decision, data, document, display, manual loop, and many other specific symbols. The meaning for each symbol offered by ConceptDraw gives the presentation about their proposed use in professional Flowcharts for business and technical processes, software algorithms, well-developed structures of web sites, Workflow diagrams, Process flow diagram and correlation in developing on-line instructional projects or business process system. Use of ready flow chart symbols in diagrams is incredibly useful - you need simply drag desired from the libraries to your document and arrange them in required order. There are a few serious alternatives to Visio for Mac, one of them is ConceptDraw DIAGRAM. It is one of the main contender with the most similar features and capabilities.

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.

ConceptDraw DIAGRAM ER Diagram Tool

Entity-relationship model, also called ER-model, is the main tool of domain modeling on the stage of conceptual design. The modeling of domain data structures is based on the use of graphical tools - Entity-Relationship diagrams (ER-diagrams). The core concepts of ER-Diagram are entity, attribute and relationship. ER-diagram lets visually represent the entities, helps effectively document all properties of designed system and to detail the data storages. To represent the elements at ER-model are commonly used Chen’s notation and Crow’s foot notation, each has its pros and cons. The entity on ER-diagram is represented in the form of rectangle, which specifies its name. An attribute is a property of the entity and relationship is an interaction between the entities. The relationship between two entities is called binary, between more than two entities - ternary. Specific software, such as ConceptDraw DIAGRAM with Entity-Relationship Diagram (ERD) solution from ConceptDraw Solution Park is helpful for easy creation Entity-Relationship Diagrams.

Flow Chart Symbols

The Flowcharts are incredibly useful and popular tool used in science, business, software development, analytics, engineering, marketing, manufacturing, administration, architecture, government, politics, and many other fields thanks to a variety of existing types of flowcharts. A Flowchart is a visual graphical representation of the process, algorithm, or the set of steps taken for problem's solution. Widely used for designing, visualizing and documenting simple and complex processes and programs, they effectively help to understand the process and to find easier the flaws if they are. Each flowchart type supposes the use of its own set of notations for drawing corresponding diagram, which includes the symbols of process, decision, data, document, data base, termination, initiation processes, processing loops, conditions, etc. It is easily design a Flowchart using the special professional flowchart maker - ConceptDraw DIAGRAM diagram software with numerous predesigned flow chart symbols grouped in libraries of Flowcharts solution from ConceptDraw Solution Park.

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.

Flowchart Components

The ConceptDraw Flowchart component includes a set of samples and templates. This geathered as flowchart maker toolbox which focused on drawing flowcharts of any industry standards.

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.

Entity Relationship Diagram Symbols

The semantic modeling method nowadays is successfully applied in database structure design. It is effective method of modeling the data structures, which is based on the meaning of these data. As a tool of semantic modeling, there are used different types of Entity-Relationship Diagrams. Entity Relationship Diagram (ERD) is applied to visually and clearly represent a structure of a business database. The main components of ERDs are: entity, relation and attributes. An entity is a class of similar objects in the model, each entity is depicted in the form of rectangle and has the name expressed by a noun. Relation is shown in the form of non-directional line that connects two entities. There are several notation styles used for ERDs: information engineering style, Chen style, Bachman style, Martin Style. The Entity Relationship Diagram symbols used for professional ERD drawing are predesigned by professionals and collected in the libraries of the Entity-Relationship Diagram (ERD) solution for ConceptDraw DIAGRAM software.