What is Software Testing Life Cycle (STLC) & STLC Phases
In this post, we’ll take you through everything you need to know about Software Testing Life Cycle (STLC). In the earlier post, we have learnt what is Software Testing and Software Development Life Cycle.
We’ll start with a Definition of STLC, STLC Phases and the following.
What is STLC?
Software Testing Life Cycle (STLC) identifies what test activities to carry out and when to accomplish those test activities. Even though testing differs between organizations, there is a testing life cycle.
Don’t Miss: Manual Testing Complete Tutorial
STLC Video Tutorial
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Phases of STLC

The different phases of the Software Testing Life Cycle Model (STLC Model) are:
- Requirement Analysis
- Test Planning
- Test Design
- Test Environment Setup
- Test Execution
- Test Closure
Every phase of STLC (Software Testing Life Cycle) has a definite Entry and Exit Criteria.
1. Requirement Analysis
The entry criteria for this phase is the BRS (Business Requirement Specification) document. During this phase, the test team studies and analyzes the requirements from a testing perspective.
This phase helps to identify whether the requirements are testable or not. If any requirement is not testable, the test team can communicate with various stakeholders (Client, Business Analyst, Technical Leads, System Architects, etc) during this phase so that the mitigation strategy can be planned.
Entry Criteria: BRS (Business Requirement Specification)
Deliverables: List of all testable requirements, Automation feasibility report (if applicable)
Must Read: Test Strategy In Depth Explanation
2. Test Planning:
Test planning is the first step in the testing process.
In this phase typically Test Manager/Test Lead involves determining the effort and cost estimates for the entire project. Preparation of the Test Plan will be done based on the requirement analysis.
Activities like resource planning, determining roles and responsibilities, tool selection (if automation), training requirements, etc., carried out in this phase.
The deliverables of this phase are Test Plan & Effort estimation documents.
Entry Criteria: Requirements Documents
Deliverables: Test Strategy, Test Plan, and Test Effort estimation document.
Must Read: How To Write A Good Test Plan
3. Test Design:
The test team starts with test case development activity here in this phase. Testers prepares test cases, test scripts (if automation), and test data.
Once the test cases are ready then these test cases are reviewed by peer members or team lead.
Also, the test team prepares the Requirement Traceability Matrix (RTM). RTM traces the requirements to the test cases that are needed to verify whether the requirements are fulfilled. The deliverables of this phase are Test Cases, Test Scripts, Test Data, Requirements Traceability Matrix
Entry Criteria: Requirements Documents (Updated version of unclear or missing requirement)
Deliverables: Test cases, Test Scripts (if automation), Test data.
In this phase, Selenium would be the most popular tool to use. However, its complexities and programming experience needed to Python or C# would definitely pose a problem to your manual QAs and automation freshers.
Here, Katalon Studio would be your go-to choice in simplifying Selenium’s essential capabilities through codeless automation, built-in keywords, and pre-defined artifact templates for test suites.
Must Read: How To Write Test Cases
4. Test Environment Setup:
This phase can be started in parallel with the Test design phase.
The test environment setup is done based on the hardware and software requirement list. In some cases, the test team may not be involved in this phase. The development team or customer provides the test environment.
Meanwhile, the test team should prepare the smoke test cases to check the readiness of the given test environment.
Entry Criteria: Test Plan, Smoke Test cases, Test Data
Deliverables: Test Environment. Smoke Test Results.
5. Test Execution:
The test team starts executing the test cases based on the planned test cases. If a test case result is Pass/Fail then the same should be updated in the test cases.
The defect report should be prepared for failed test cases and should be reported to the Development Team through a bug tracking tool for fixing the defects.
Retesting will be performed once the defect was fixed. Click here to see the Bug Life Cycle.
Entry Criteria: Test Plan document, Test cases, Test data, Test Environment.
Deliverables: Test case execution report, Defect report, RTM
Must Read: How To Write An Effective Defect Report
6. Test Closure:
The final stage where we prepare Test Closure Report, Test Metrics.
The testing team will be called out for a meeting to evaluate cycle completion criteria based on Test coverage, Quality, Time, Cost, Software, Business objectives.
The test team analyses the test artifacts (such as Test cases, Defect reports, etc.,) to identify strategies that have to be implemented in the future, which will help to remove process bottlenecks in the upcoming projects.
Test metrics and Test closure report will be prepared based on the above criteria.
Entry Criteria: Test Case Execution report (make sure there are no high severity defects opened), Defect report
Deliverables: Test Closure report, Test metrics
Must Read: Test Metrics
STLC Phases (Entry and Exit Criteria)
STLC Phase | Entry Criteria | Exit Criteria | Deliverables |
---|---|---|---|
Requirement Analysis | Requirements specification document, Acceptance criteria document, Application architectural document | Signed off RTM, Signed off Automation feasiblity report | List of all testable requirements, Automation feasibility report (if applicable) |
Test Planning | Requirements Documents, Automation feasbility report | Approved Test plan document, Approved Test strategy document, Signed off effort estimation document | Test Strategy, Test Plan, and Test Effort estimation document. |
Test Design | Requirements Documents (Updated version of unclear or missing requirement), RTM, Test Plan, Test Estimation Document, Automation Analysis Report | Reviewed and approved test cases, test scripts, test data | Test cases, Test Scripts (if automation), Test data. |
Test Environment Setup | Test Plan, Test environment setup plan, Smoke Test cases, Test Data | Working test environment setup, Valid test data setup, Successful somke test | Test Environment. Smoke Test Results. |
Test Execution | Test Plan document, Test cases, Test Scripts, Test data, Test Environment. | Execute all planned test cases, Log all defects found | Test case execution report, Defect reports, RTM |
Test Closure | Testing has been completed, Test Case Execution report (make sure there are no high severity defects opened) | Signed off Test Closure report | Test Closure report, Test metrics |
Difference between STLC vs SDLC

Check this detailed guide on difference between SDLC & STLC
Conclusion:
Software Testing Life Cycle is a systematic way of performing testing. It gives better product quality, quick bug fixing results, and effective and efficient test results.
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Related Posts:
- Software Development Life Cycle (SDLC)
- Bug Life Cycle (Defect Life Cycle)
- Test Metrics
- Requirement Traceability Metrics (RTM)
- Test Artifacts / Test Deliverables
- How To Write Test Strategy
- How To Write Test Plan
In test execution phase, forgot to provide a URL for bug life cycle. I think, I did static testing(review) here 🙂 Good explanation, Thank you.
and its a low severity defect
Hi Geetanjali. Thanks for pointing out. 🙂 Your inputs are welcome. Keep visiting.