Comparison – STLC and SDLC

In this chapter, we will understand the factors of comparison between STLC and SDLC. Let us consider the following points and thereby, compare STLC and SDLC.  STLC is part of SDLC. It can be said that STLC is a subset of the SDLC set.

1. STLC is limited to the testing phase where quality of software or product ensures. SDLC has vast and vital role in complete development of a software or product.
2. However, STLC is a very important phase of SDLC and the final product or the software cannot be released without passing through the STLC process.
3. STLC is also a part of the post-release/ update cycle, the maintenance phase of SDLC where known defects get fixed or a new functionality is added to the software. 

The following table lists down the factors of comparison between SDLC and STLC based on their phases:

SDLC
1. Requirement Gathering

• Business Analyst gathers requirements.
• Development team analyzes the requirements.
• After high level, the development team starts analyzing from the architecture and the design perspective.

2. Design

• The architecture of SDLC helps you develop a high-level and low-level design of the software based on the requirements.
• Business Analyst works on the mocker of UI design.
• Once the design is completed, it is signed off by the stakeholders.

3. Development

• Development team starts developing the software.
• Integrate with different systems.
• Once all integration is done, a ready to test software or product is provided.

4. Environment Set up

• Development team sets up a test environment with developed product to validate.

5. Testing

• The actual testing is carried out in this phase. It includes unit testing, integration testing, system testing, defect retesting, regression testing, etc.
• The Development team fixes the bug reported, if any and sends it back to the tester for retesting.
• UAT testing performs here after getting sign off from SIT testing.

6. Deployment/ Product Release

• Once sign-off is received from various testing team, application is deployed in prod environment for real end users

7. Maintenance

• It covers the post deployment supports, enhancement and updates, if any.

STLC

1. Requirement Gathering

• Testing team reviews and analyzes the SRD document.
• Identifies the testing requirements - Scope, Verification and Validation key points.
• Reviews the requirements for logical and functional relationship among various modules. This helps in the identification of gaps at an early stage.

2. Design

• In STLC, either the Test Architect or a Test Lead usually plan the test strategy.
• Identifies the testing points.
• Resource allocation and timelines are finalized here.

3. Development

• Testing team writes the test scenarios to validate the quality of the product.
• Detailed test cases are written for all modules along with expected behavior.
• The prerequisites and the entry and exit criteria of a test module are identified here.

4. Environment Set up

• The Test team confirms the environment set up based on the prerequisites.
• Performs smoke testing to make sure the environment is stable for the product to be tested.

5. Testing

• System Integration testing starts based on the test cases.
• Defects reported, if any, get retested and fixed.
• Regression testing is performed here and the product is signed off once it meets the exit criteria.

6. Deployment/ Product Release

• Smoke and sanity testing in production environment is completed here as soon as product is deployed.
• Test reports and matrix preparation are done by testing team to analyze the product.

7. Maintenance

• In this phase, the maintaining of test cases, regression suits and automation scripts take place based on the enhancement and updates.