Design Document

1. Introduction of Design Document

2. Entity Relationship Diagram (ERD)3. Sequence Diagrams

4. Architecture Design Diagram

5. Class Diagram

6. Database Design7. Interface Design8. Test Cases

1) Introduction of Design DocumentThisdocumentcontains the high-level and low-leveldesign specifications for the Software Requirements Specifications (SRS)

1 Introduction

The Software Design Document is a document to provide documentation which will be used to aid in software development by providing the details for how the software should be built. Within the Software Design Document are narrative and graphical documentation of the software design for the project including use case models, sequence diagrams, collaboration models, object behavior models, and other supporting requirement information. 2) Entity Relationship Diagram (ERD)An entity-relationship diagram (ERD) is a graphical representation of an information system that shows the relationship between people, objects, places, concepts or events within that system. An ERD is adata modelingtechnique that can help define business processes and can be used as the foundation for arelational database.

Examples:Consider the example of a database that contains information on the residents of a city. The ER diagram shown in the image above contains twoentities-- people and cities. There is a single "Lives In" relationship. Each person lives in only one city, but each city can house many people.

There are three types of relationships between entities:

1. One-to-One

One instance of an entity (A) is associated with one other instance of another entity (B). 2. One-to-Many

One instance of an entity (A) is associated with zero, one or many instances of another entity (B), but for one instance of entity B there is only one instance of entity A.

3. Many-to-Many

One instance of an entity (A) is associated with one, zero or many instances of another entity (B), and one instance of entity B is associated with one, zero or many instances of entity.

3 ) Sequence DiagramsAsequence diagramis used primarily to show the interactions between objects that are represented as lifelines in a sequential order.

4) Architecture Design Diagram

Anarchitecturalmodel (in software) is a rich and rigorousdiagram, created using available standards, in which the primary concern is to illustrate a specific set of tradeoffs inherent in the structure anddesignof a system or ecosystem."Architecture" can mean: A general term to describe buildings and other physical structures. The art and science ofdesigningbuildings and (some) nonbuilding structures. The style ofdesignand method of construction of buildings and other physical structures. 5) Class Diagram

Aclass diagramis an illustration of the relationships and source code dependencies amongclassesin the Unified Modeling Language (UML). In this context, aclassdefines the methods and variables in an object, which is a specific entity in a program or the unit of code representing that entity.

6) Database DesignDatabase designis the process of producing a detailed data model of adatabase. This logical data model contains all the needed logical and physicaldesignchoices and physical storage parameters needed to generate adesignin a datadefinitionlanguage, which can then be used to create adatabase.

7)Interface DesignUserinterface design(UID) or userinterfaceengineering is thedesign of websites, computers, appliances, machines, mobile communication devices, and software applications with the focus on the user's experience and interaction.

8)Test CasesAtest case, in software engineering, is a set of conditions under which a tester will determine whether an application, software system or one of its features is working as it was originally established for it to do.