Software Development Life Cycle VS Software Testing Life Cycle

SDLC (Software Development Life Cycle):

It deals with entire software product development process.

It involves all the people who are involved in product development from Requirement gathering to maintenance phase, which means Developers, QA, Stakeholders, Customers, Clients/Business, support/Maintenance teams.

The different phases involved in SDLC are:

  • Requirement Gathering
  • Designing
  • Coding/Implementation
  • Testing
  • Deployment
  • Maintenance


STLC (Software Testing Life Cycle):

It refers to all the activities done by testing team only from Test Requirement Analysis to Test Closure Activities, which means only QA Team involved in it.

The different phases in STLC are:

  • Requirement Analysis
  • Test Planning
  • Test Analysis and Design
  • Test Case Development
  • Test Environment Setup
  • Test Execution
  • Exit Criteria Evaluation and Reporting
  • Test Closure


Difference between SDLC and STLC:




 it is a systematic approach to develop a software.

The process of testing a software in a well planned & systematic way

Requirements Gathering

Gathering of requirements is carried out by the BA (Business Analyst) where the development team will analyses the requirements right from the design architecture to the coding into perspective. 

Here QA Team, uses requirements gathering for testing, review, and analysis of the requirements.

Design Phase

Here Technical architect comes whose function is to ensure that high level and low designs of the software are met.

Soetimes, the BA (business analyst) also comes in here to create a user interface design for the application. 

Here Test architect acting as the lead manager in doing the test planning and the identification of the high level testing points. 

coding or development phase

Here actual development which refers to coding occurs (Development Team) and this is based on the design architecture. 


Here QA Team focus on writing the detailed test design activities (Preparation Test scenarios and Test cases).

Testing phase

In this phase, actual testing of the developed code. Within this phase, different levels of testing will be done. 

Here test execution too done in addition to reporting any errors/defects that are found.  

Here manual reporting, automation, and testing is performed to ensure that the developed code functions as it should.

Retesting and regression

testing are also performed within this stage. 

Deployment phase

Deploys applications that have passed over last four stages

This will be the final testing and implementation stage.

Testing is done & a final report is prepared.

Maintenance phase

It features post production and deployment support and follow-up with enhancements as they continue to be developed.

Features updates and maintenance of test plans, and testing and support of test phases, as well as enhancements as part of maintenance.

SDLC-VS-STLCNote: STLC is a part in SDLC