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.

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.

Entity Relationship Diagram - ERD - Software for Design Crows Foot ER Diagrams

ER-model is a data model which lets describe the conceptual schemes in a specific subject area. It can help to highlight the key entities and specify relationships that can be established between these entities. During the database design, it is realized the transformation of ER model into certain database scheme based on the chosen data model (relational, object, network, etc.). There are used two notations for ERDs: Crow's Foot and Chen's. Crow's Foot notation proposed by Gordon Everest represents the entity by rectangle containing its name (name must be unique within this model), and relation - by the line which links two entities involved in relationship. The relationship's plurality is graphically indicated by a "plug" on the end of the link, the optionality - by a circle. Entity-Relationship Diagrams based on Crow's Foot notation can be easily drawn using the ConceptDraw DIAGRAM. Extended with Entity-Relationship Diagram (ERD) solution, it is the best ERD diagrams software with powerful tools and ready design elements for Crow's Foot and Chen notations.

Components of ER Diagram

Entity-Relationship model gives the possibility to visually describe a database using the components of ER Diagram, entity relationship stencils, relationship symbols, work flow shapes. ER-diagram lets represent the data or entities, attributes of these entities and relationships between them, using standardized Crow’s Foot notation icons or Chen’s notation icons. An entity is an object of the real world, it can exist independently and has the instances which differ in attribute values (properties). The attributes give an unambiguous (uniquely) identification for the instance and are called the primary key, this key can be composite and combine several attributes. ConceptDraw DIAGRAM is a professional software available with Entity-Relationship Diagram (ERD) solution from Software Development area that lets create ERDs for various database systems, using Crow’s Foot and Chen’s notations. It is invaluable tool for software engineers and developers, it supports ODBC-compatible databases (Oracle, MySQL, MS Access, MS SQL, InterBase, Firebird and others).

Design Element: Crows Foot for Entity Relationship Diagram - ERD

Entity-Relationship Diagram (ERD) is ideal tool that helps execute the detalization of data warehouse for a given designed system, lets to document the system's entities, attributes (objects' properties), and their interactions each other (relationships). Creation of an ERD requires the choice of specific set of notations, which the best suits for your database design. Two notations - Chen’s and Crow's Foot are applied for ERDs design. Chen's notation was developed first and has linguistic approach, the boxes represent the entities and are considered as nouns, relationships between them are shown as diamonds in a verb form. Over time Chen’s style was adapted into the popular standard - Crow’s Foot notation, where entities are shown as boxes and relationships - as labeled lines. ConceptDraw DIAGRAM software supplied with Entity-Relationship Diagram (ERD) solution offers samples and templates of ER diagrams, and also ready-to-use vector design elements - ERD Crow′s Foot and Chen's notation icons for easy designing your own ER diagrams for depicting databases.

Notation & Symbols for ERD

The ER diagram is constructed from the specific ERD graphic elements. There are used 2 types of ERD notations: Chen and Crow's Foot. A complete set of work flow shapes, notation & symbols for ERD, entity relationship stencils, included in Entity-Relationship Diagram (ERD) solution for ConceptDraw DIAGRAM software, makes drawing diagrams based on ERD notation as smooth as possible.

UML Collaboration Diagram (UML2.0)

UML Collaboration Diagram depicts the interactions between objects or parts in terms of sequenced messages and describes both the static structure and dynamic behavior of a system. Rapid UML solution provides templates, examples and libraries of stencils for quick and easy drawing all the types of system and software engineering diagrams according to UML 2.4 and 1.2 notations.

Yourdon and Coad Diagram

The vector stencils library Yourdon and Coad Notation from the solution OOAD contains specific symbols of the Yourdon and Coad notation such as data store symbol, data process symbol, loop symbol for ConceptDraw DIAGRAM diagramming and vector drawing software. The OOAD solution is contained in the Software Development area of ConceptDraw Solution Park.

Data Flow Diagrams

Data Flow Diagram (DFD) is a special chart type which lets graphically illustrate the "flow" of data through an information system. So the Data Flow Diagrams can be successfully used for visualization of data processing or structured design, for creation an overview of the system, for business process modeling, for exploring the high-level design in terms of data flows and documenting the major data flows. Inclusion of powerful Data Flow Diagrams solution to the Software Development area of ConceptDraw Solution Park makes the ConceptDraw DIAGRAM a beneficial data flow diagramming software and supplies it with numerous collection of quick-start templates, professionaly designed samples, and extensive range of ready-for-use vector objects consisting the Data Flow Diagrams, Gane-Sarson Notation, and Yourdon and Coad Notation libraries. Use the ConceptDraw DIAGRAM application to design easy and quickly the Data Flow Diagrams including the data storages, data flows, external entities, functional transforms, control transforms and signals.