Entity Relationship Diagram Software Engineering

Entity Relationship Diagram (aka ER Diagram, E-R Diagram, ERD) is a time-tested and widespread software development and software engineering method for data modeling, illustrating the logical structure of databases and system design. For ERDs construction are used three basic elements: entities, attributes, and relationships. Chen's notation for ERD supposes the use of rectangles (boxes) to represent entities and diamonds to depict relationships between first-class objects. This notation is popular when creating conceptual data models of information systems. Another standardized notation for ER diagrams is Crow's foot notation. ConceptDraw DIAGRAM as a powerful Entity Relationship Diagram software engineering provides the tools of Entity-Relationship Diagram (ERD) solution from Software Development area of ConceptDraw Solution Park for instantly describing databases using ERDs of Crow’s Foot and Chen’s notations. Use the predesigned vector elements for both these notations from 2 libraries included to Entity-Relationship Diagram (ERD) solution.

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.

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.

Data structure diagram with ConceptDraw DIAGRAM

Data structure diagram (DSD) is intended for description of conceptual models of data (concepts and connections between them) in the graphic format for more obviousness. Data structure diagram includes entities description, connections between them and obligatory conditions and requirements which connect them. Create Data structure diagram with ConceptDraw DIAGRAM.

E-R Diagrams

Complexity of databases increases day by day, due to this the Entity relationship models and E-R diagrams become more and more popular, and now are an important part of database design. E-R diagrams created at ConceptDraw DIAGRAM allow visually and graphically represent structure and design of databases.

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.

UML Class Diagram Generalization Example UML Diagrams

This sample was created in ConceptDraw DIAGRAM diagramming and vector drawing software using the UML Class Diagram library of the Rapid UML Solution from the Software Development area of ConceptDraw Solution Park. This sample describes the use of the classes, the generalization associations between them, the multiplicity of associations and constraints. Provided UML diagram is one of the examples set that are part of Rapid UML solution.

JSD - Jackson system development

Jackson System Development (JSD) is a linear method of system development created by Michael A. Jackson and John Cameron in the 1980s. It comprises the whole software life cycle directly or providing a framework for more specialized techniques. When implementing the Jackson System Development method and designing JSD diagrams, you can succesfully use the powerful and helpful tools of ConceptDraw DIAGRAM software extended with Entity-Relationship Diagram (ERD) solution from the Software Development area of ConceptDraw Solution Park.