Software Testing Life Cycle (STLC) is used to test software and ensure that quality requirements are met. Testing is done methodically across several stages. STLC phases are repeated throughout the entire cycle until the software is accepted for release. 

Software Testing Life Cycle Process (STLC) Process

Once the developers are done programming the software, it is deployed in the testing environment. The testing team tests the application’s functionality to ensure it works according to the customer’s requirements. When the Quality Assurance team finds any bugs in the software, they inform the developers. The testing team provides an in-depth report about the bugs to the developers. The development team fixes the bugs and sends the software to be tested again. This process is repeated until the application has no bugs and can be used by the end user without any problems. 

There are a few activities that are included in the STLC life cycle

  • Analysis of client’s system requirements. 
  • Create a traceability matrix. A traceability matrix is a document that determines project completeness by comparing application features with the original requirements. 
  • Prioritize features. The way that you prioritize features is how they will be targeted by the development team. If a particular feature is the number one priority, then the development team will work on adding that feature to the software first. 
  • Identify the testing techniques that you will need for each feature. 
  • Analyze a method to automate tasks. 
  • Identify information about the testing environment. 

Software Testing Cycle Purpose

STLC includes various stages such as planning, control, implementation, standardization, etc. All this leads to the conclusion that the purpose of STLC is not just to test the developed software but also the following: 

  • Removing an application’s shortcomings during the initial stage of development. 
  • Increasing transparency and quality of the developed software. The team of developers also has accountability as they will have to collaborate with another team.
  •  You get a lot of control over the quality of the software and the user experience. 
  • During the software development phase, developers are too busy to add features to the application to introspect. During the testing cycle, you can examine if you have achieved the project’s goals. 
  • Meet the quality requirements of not only the client but of the users too. 
  • You can add additional features once development is finished because you will know that the other existing features do not have any bugs. 
  • You can apply time constraints to the testing cycle. 

Software Testing Life Cycle Phases

In the entire software testing life cycle, there are six stages or phases with specific entrance and exit criteria, associated tasks, and deliverables. Sometimes another phase can only begin once the preceding phase is over. However, some phases can be executed simultaneously. The beginning and ending of phases are determined by the entry and exit criteria. Each phase has different entry and exit criteria. Your team must have a complete understanding of the STLC to properly test the software. 

Phase 1: Requirement Analysis

In this stage, testable features gathered with the help of the SDLC are analyzed. Testing teams may have to communicate their requirements to the stakeholders. If their requirements are met, then the software will have all the planned features. This step also assesses if the testing capacity can be automated. 

Entry criteria: Requirements or needs, applicability levels, and the expected software architecture. 

Exit criteria: approved automation feasibility study and requirement traceability matrix (RTM).

Phase 2: Planning

The entire strategy of the test is highlighted in a document. This plan includes details like needed tools, testing steps, and team responsibilities. When planning, you do risk and cost analysis and create a timetable for the testing process. Without a listed timeline, your testing project is likely going to fail. 

  • Entry Criteria- requirement analysis, requirements traceability matrix, and automation feasibility report. 
  • Exit Criteria- A test plan which is approved by the stakeholders, including timetable and risk/cost analysis. 

Phase 3: Creating test cases

Test cases are made in this stage. Each test case includes the inputs, the procedures, critical circumstances, and the expected results. A test case should be direct, productive, and flexible. 

Entry Criteria: Test plan approval, with dates and a cost/risk analysis.

Exit Criteria: accepted automation scripts and test cases.

Phase 4: Establishing the Test Environment

Environments for testing are set up and deployed at this step. TestComplete, Selenium, Appium, and Katalon Studio are a few examples of the testing tools that could be used in this phase. Setting up test servers is occasionally part of this process. After environments are deployed, smoke tests are run to ensure they function with all intended features.

Definitions of the project’s architecture and the system design are entry criteria.

Test environments and test cases approved as valid are exit criteria.

Phase 5: Execution of Tests

When you already have test cases, you can test features by deploying them in the test environment. Test results are organized later on and compared to the expectations of the client. If there are gaps between the expectations and the current test results, then feedback is provided to the development team. The development teams get back to work to eliminate bugs, so that client expectations are met. 

Entry Criteria: All departure criteria from earlier steps serve. 

Exit Criteria: All tests are run, and the outcomes are recorded.

Phase 6: Closing the STLC life cycle.

This is the ending phase of the STLC, during which a test result report is created. This report needs to contain comparisons between the expected and actual results and a summary of the complete testing procedure. These comparisons consider the goals achieved, the time spent, the overall costs, the test coverage, and any flaws discovered.

Entry Criteria: Test scores and reporting from every prior round. 

Exit Criteria: test closing report delivered and approved.

STLC Benefits

If the STLC did not have any benefits, then every organization would not be following it. 

  • Project requirements are analyzed because of STLC. By the end, developers are aware of the project requirements, which helps them be consistent. 
  • Clear goals for test subjects, which helps track the progress of the software. 
  • Tests are designed in a meaningful manner. 
  • Project specifications are clear, which helps the testing team. 
  • The systematic approach quickly eliminates the bugs in the software and makes it ready to use. 


Everyone is confused about when the testing process can be stopped. The answer is extremely simple, as soon as the exit criteria are met, you can stop the testing process. Test managers, team leads, clients, and other stakeholders decide when to stop the testing process. The testing goals should be met when it is stopped, if they are not met, the process will start again.

When your team completes an STLC, they generate a test report. This report will include testing outcomes, and evaluations and can be used as a document that advocates for the release of the application. When the testing process is over, it is important to generate this report. Only after you have generated the testing report is your job done. When you generate this report, you will be able to see how the test strategies you used this time can be improved in the future. Everyone should aim for good quality software and continue with the best practices for the next time. 

When you want a quality product, you can either work with the SDLC approach or the STLC approach. Most developers usually work with both approaches. 

It is not a good idea to find bugs in the last stage of SDLC anymore. Spending too many resources to fix bugs in the end also leads to lower efficiency. Using resources and time appropriately makes the testing process easy. Therefore, when you follow STLC, you will get bugs fixed quickly. With STLC, you get a high-quality application in less time. You will get happy customers, a good reputation, customer loyalty, and an increased ROI if you go with STLC.