Software Testing Life Cycle: What Is It?

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Software Testing Life Cycle: What Is It?

Key Points

  • The Software Testing Life Cycle (STLC) is a crucial process that involves testing and retesting the different functions of an application to catch and fix bugs before release.
  • The STLC consists of six steps: Requirement Analysis, Test Planning, Test Case Development, Test Environment Setup, Test Execution, and Test Closure.
  • The Requirement Analysis phase involves creating a Requirement Traceability Matrix (RTM).
  • Test Planning is the stage where all tests are defined and the effort and cost of the trial procedures are calculated.
  • Test Execution is an iterative process where the testing team performs test cases until the software meets the desired results.

The Software Testing Life Cycle (STLC) is crucial to a program’s development. It’s a process that involves testing and retesting the different functions of an application to ensure that any bugs and problems within the code are caught and fixed before the final release to the public. Several steps make up the STLC. So, let’s examine those.

Steps of the Software Testing Life Cycle

There are six steps in the STLC: Requirement Analysis, Test Planning, Test Case Development, Test Environment Setup, Test Execution, and Test Closure. As the names imply, this process only covers the testing phases of the application’s production. 

A development team will begin the STLC when the stakeholders clearly define the application’s requirements. This step-by-step process will ensure the software’s quality and operation. The first steps of the methodology involve identifying what the program needs to do.

Additionally, the team will need to determine what to test to ensure that functionality. The final stages are the actual testing procedures. Each stage in the process has clear-cut Entry and Exit Criteria. Entry Criteria are the requirements that must be met for the step to begin. Conversely, Exit ones are the necessary conditions to meet to move to the following phase.

Step 1: Requirement Analysis

software testing life cycle
The Software Testing Life Cycle begins with the Requirements Analysis phase.


This step is the first in the STLC. It begins when the stakeholders lay down the requirements for the application’s functionality. Typically, they will provide the development team with a document that outlines the software’s operation needs. This document is known as a “Software Requirements Document,” or SRD. The procedures performed in the Requirement Analysis phase are as follows:

  • The team will review the SRD and any other documentation the stakeholders provide
  • The team will provide a brief overview of what testing processes are necessary to achieve maximum code quality
  • They will interview key stakeholders to collect more information that may have been accidentally omitted
  • The team will find and assess any contradictions or inconsistencies in the documentation
  • They will gather information about any requirements they need to complete
  • The team will identify risks that may hinder the testing process

During this process, the team will create a Requirement Traceability Matrix (RTM), a document that helps tie the SRD to the testing phase by mapping requirements to test cases. The team will update and rework this document until they completely understand the software’s functionality.

Once the RTM is finished, the team can move on to the next steps in development and testing. The Requirements Analysis phase is crucial to ensuring that the development team is focused on the most critical aspects of the SRD. Additionally, it guarantees that the testing team can produce high-quality results.

Step 2: Test Planning

Test Planning is when all the tests the team intends to perform on the software are defined and listed. This phase is generally the most efficient stage in the STLC. Additionally, the team will calculate the required effort and projected cost of the trial procedures. So, this stage begins immediately following the Requirement Analysis process.

Activities performed during the Test Planning phase are as follows:

  • The team will detail the testing scope and objectives
  • They will identify projected software testing strategies by choosing the methodology and techniques during trials
  • They will describe the needs for the test environment and determine what resources will be needed
  • The team will decide what test cases to execute and describe what test data will be collected and documented
  • They will estimate the monetary and time costs of the selected testing process
  • The team will explain what the selected tests can deliver and milestones to achieve
  • They will decide on roles and responsibilities within the testing team
  • The team will review, submit, and approve the final plan

When this phase concludes, both the development and testing teams should have a clear plan for moving forward with the production and testing of core application functions. They should understand the projected testing process, its scope, and what they should deliver through trials. Strong organization during this stage will ensure high-quality results during evaluation.

Step 3: Test Case Development

In this phase, the development team identifies specific test cases — sets of actions performed on a system to see whether it satisfies software requirements and efficiently completes core functions. The team will document the experiments they want the testing team to perform during trials.

Once the development team has prepared a list of test cases, the quality assurance team will review them. This way, no test cases are accidentally omitted. The QA squad will take note of any additional test cases they recommend for the testing team, which the development team will review.

These teams will pass these cases back and forth until they come to a consensus on what trials the testing squad needs to perform. The activities that occur during the Test Case Development phase are as follows:

  • The team will detail test cases that the development team thinks the testing team should perform
  • They will document the chosen test cases in concise, clear, easily understood writing
  • The team will produce test data and scenarios that the testing team can use during test cases
  • They will detail the expected results of each test case
  • The team will review and approve the test case documentation
  • They will update and improve the RTM

Upon the conclusion of this phase, all teams should have clear, concise, easily understood documentation of the test cases that the testing team will perform. The development team should program the application with these test cases in mind, while the trials team ensures that the final product meets the requirements of the SRD.

The quality assurance team will review the test cases to ensure they wholly and adequately cover the basis of the SRD’s documentation. This process will guarantee smooth development and testing.

Step 4: Test Environment Setup

This crucial step in the STLC is when the team sets up the exact environment under which the software gets tested. Sometimes, this step gets performed as part of a more comprehensive process during test case development. But, in many cases, it’s performed as an independent activity.

Activities performed during the Test Environment Setup phase may include:

  • Determining the minimum system specifications for running the software
  • Identifying the ideal and unideal software environments to test during the testing proctoring
  • Procuring hardware and software to produce ideal and unideal results

Step 5: Test Execution

software testing life cycle
During the Test Execution phase, the testing team performs the test cases outlined by the development team in the Test Case Development stage.

©DC Studio/Shutterstock.com

As the name implies, this is the stage of the STLC where the testing team gets the application and starts to perform the test cases outlined by the development team in the Test Planning and Test Case Development phases. Activities conducted during the Test Execution stage are as follows:

  • Test data will be prepared and loaded into the program for testing
  • Any necessary software, hardware, or network environments are procured and assembled
  • Actual testing will be performed: the team will take the documentation from the Test Planning and Test Case Development phases and go through the various experiments with the software
  • The testing team will log any defects and bugs found during the test cases, including information about the severity and priority based on the SRD
  • Test result analysis will also happen during this phase: the team will take the results from their experiments and determine what changes need to be made
  • Tests will also be documented and reported to stakeholders during this process

Test execution is not a one-and-done procedure; it’s iterative, meaning the team will repeatedly perform the testing process until the software has achieved the desired results. Once the application has passed the testing procedure with all defects fixed to be fit for release to the public, the program will enter the next phase of the STLC.

Step 6: Test Closure

The Test Closure phase aims to guarantee that all relevant testing activities have been completed and the software is ready for release to the public. All testing has ended in the STLC, and the team has documented the results.

Now, the team should have a good handle on the software’s stability and reliability. They should be confident that the program meets the requirements outlined in the SRD. They will also document the testing process and anything they can use to improve future software STLCs.

The following activities will take place during the Test Closure phase:

  • The team will create a test summary report documenting statistics such as the number of test cases performed, the number of defects found, and overall pass/ fail rates
  • They will track the defects found in the program during testing and how they were managed until they were resolved
  • The test environment will be cleaned up and archive test data and artifacts
  • The team will create a test closure report, which documents all test-related activities, objectives, scope, resources, and schedule
  • They will document and transfer any relevant knowledge about the software’s maintenance to the shareholders who will maintain it going forward
  • Finally, they will collect feedback about the testing process to improve future STLCs

The test closure phase is about documenting the test itself and improving future testing batteries by making sure that any essential lessons are brought into future trials. It is to ensure the software is prepared for its release and to guarantee that this and future testing processes move in the most organized and efficient ways possible.

Frequently Asked Questions

What is the Software Testing Life Cycle?

The Software Testing Life Cycle (STLC) is a defined methodology for ensuring a program is prepared for release to the public with as few bugs and defects as possible.

What are the steps of the Software Testing Life Cycle?

The six steps of the Software Testing Life Cycle are Requirement Analysis, Test Planning, Test Case Development, Test Environment Setup, Test Execution, and Test Closure.

How long does the Software Testing Life Cycle take?

The STLC can take months to years to complete, depending on the number of test cases, objectives, and scope of testing.

What is the most efficient phase of the Software Testing Life Cycle?

The STLC’s most efficient phase is usually the Test Planning stage.

What do the teams do during the Test Closure phase?

During the test closure phase, the teams document the testing process to pass the knowledge to the stakeholders, who will maintain the program from there and learn from the tests performed to improve future STLCs.

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