Software Development Life Cycle

Software development life cycle (SDLC) is a process to develop the software systematically. SDLC is also known as software life cycle and software process. SDLC have the following stages:
1) Information Gathering
In this phase, information is gathered from the customer. If some information is missing then we need to go to customer and take the required information. Mainly this is done by the Business Analyst as they are the one who are completely involved in Software Development life Cycle.
The Document Prepared during this phase is: Business Requirement Specification (BRS) or Customer Required Specification (CRS) Or User Requirement Specification (URS).
Entry Criteria: BRS OR CRS or URS.
2) Analysis Phase
In this stage the project architect team determines the features and the functions that need to be developed in the project.
Entry Criteria: BRS (Business Requirement Document)
Exit Criteria: SRS (Software Requirement Specification)

3) Design Phase
The actually flow of the project is designed here. System architects, team leads prepares the logical functionality, ER diagram, Data Flow etc. Document prepared during this phase are HLD, LLD
HLD (High Level Design): Gives the overall Hierarchy of the function.
Example: Login into Net Banking. From the root level to the least level is determined in HLD.
LLD (Low Level Design): Internal logic of the project is architect here. Focus is on the internal functionality of the program. Each and every module’s logic is defined.
Entry Criteria: SRS
Exit Criteria: Design Document.
Coding
The coding stage is a widely followed step in software development. Here the design is reduced to code for better understandability. Based on the design document, small-small modules are prepared. All the modules are summed together to form an application.

Testing
The coding stage is followed by the testing phase. This is one of the most important stages of any software development life cycle where extensive testing is done to ensure that coding done by different software developers work together in harmony and adhering to the agreed quality with the client.
Release and Maintantence
In this phase the malignance team will change the software if necessary based on customer end issues.
The are different types of Software Development Life Cycle (SDLC) models existing such as:
• RAD Model
• The General Model
• Spiral Model
• Incremental Model
• V-Shaped Model
• Waterfall Model