What is STLC?

STLC (Software Testing Life Cycle) is a systematic process used in software testing to ensure that software meets the required quality standards and is free from defects. The STLC consists of distinct phases, each with specific activities and deliverables, and it focuses entirely on the testing aspect of the software development life cycle.

Key Phases of STLC:

1. Requirement Analysis

   • Objective: Understand and analyze the software requirements to identify testable features.
   • Activities:
     • Review requirements from a testing perspective.
     • Identify types of tests (functional, non-functional, performance, security, etc.).
     • Identify test environments required for testing.
     • Prepare queries for unclear or missing requirements and communicate with stakeholders for clarification.
   • Deliverables: Requirement analysis document, testable requirements.

2. Test Planning

   • Objective: Create a test plan that defines the testing scope, strategy, schedule, resources, and deliverables.
   • Activities:
     • Define test objectives, testing criteria, and risk assessment.
     • Identify resources (hardware, software, personnel) required for testing.
     • Assign roles and responsibilities.
     • Plan test schedules and timelines.
     • Prepare test automation strategy (if applicable).
   • Deliverables: Test plan, effort estimation, risk assessment.

3. Test Case Development

   • Objective: Create test cases and test scripts to cover all identified scenarios based on the requirements.
   • Activities:
     • Write detailed test cases covering positive, negative, and edge cases.
     • Prepare test data required for the execution of test cases.
     • If automation is involved, develop automated test scripts.
     • Review test cases and scripts for accuracy and completeness.
   • Deliverables: Test cases, test scripts, test data.

4. Test Environment Setup

   • Objective: Set up the environment where testing will be executed.
   • Activities:
     • Configure necessary hardware and software for testing.
     • Install applications, databases, and other components as required.
     • Prepare test environment configuration as per the test plan.
     • Verify the environment to ensure it's ready for testing (also called "smoke testing").
   • Deliverables: Test environment set up and ready for execution.

5. Test Execution

   • Objective: Execute the test cases and log defects for any failed test cases.
   • Activities:
     • Execute test cases (manual or automated) as per the test plan.
     • Log defects for any issues encountered during testing.
     • Retest defects after they are fixed.
     • Track test results and update test cases or scripts as necessary.
     • Perform regression testing to ensure new changes do not introduce new defects.
   • Deliverables: Test execution results, defect logs, updated test cases, defect reports.

6. Test Closure

   • Objective: Finalize and evaluate the testing process and provide a report summarizing the results and lessons learned.
   • Activities:
     • Evaluate test coverage, the number of defects found, and overall quality.
     • Prepare test summary report.
     • Document lessons learned and best practices.
     • Archive test cases, scripts, and other related documents for future reference.
   • Deliverables: Test summary report, metrics, test closure report, lessons learned.

Importance of STLC:

1. Structured Testing Approach: STLC provides a well-organized, step-by-step process to ensure that testing is thorough and systematic.
2. Defect Identification: It helps in identifying defects as early as possible in the development cycle, reducing the cost of fixing issues later.
3. Improved Quality: By following the STLC phases, testers ensure that the software is tested rigorously, increasing the overall quality of the product.
4. Efficient Test Management: It helps in managing test resources, timelines, and efforts efficiently, improving the testing process.

Example:

Consider a project where a team is developing an e-commerce website. During the Requirement Analysis phase of STLC, the testers will review features like login, product search, checkout, etc., to understand the testable parts. In the Test Planning phase, they will create a test plan to determine how to test the features, who will do the testing, and what resources are needed. During Test Case Development, they will write detailed test cases to cover various scenarios for the website, such as adding items to the cart, processing payments, etc. The testing team will then execute the tests in the Test Execution phase, log defects, and provide final reports during the Test Closure phase.

Conclusion:

STLC (Software Testing Life Cycle) is a structured process designed to improve the quality of software through systematic planning, test case development, execution, and reporting. Each phase of STLC plays a critical role in ensuring that testing is thorough, defects are identified early, and the software meets the required standards before it is released to users.