The purpose of software testing is to detect errors and failures and verify their suitability. Tests can be performed manually (where testers apply their skill, knowledge, intuition, and experience) or automatically (following a test script). Testing ensures that all software system specifications are met during development and that no errors remain. However, testing is designed to provide customers with value through early defect detection as possible.

Testing occurs in different phases throughout the Software Development Life Cycle (SDLC). During each development phase or at certain checkpoints, testing may also take place. Software Testing Life Cycle (STLC) describes the different stages a piece of software passes through before it can be released for use (STLC). This article discusses software testing fundamentals, phases and comparisons related to software testing. Let’s get into the details!

What is the Software Testing Life Cycle?

A Software Testing Life Cycle is an iterative, cyclical process that prevents software errors. It encompasses test analysis, planning, design, setup, execution, and test closure. A single test cannot ensure that a software product is error-free due to its complexity. As a result, each phase of the Software Testing Life Cycle includes multiple tests. Throughout a project’s life cycle, different types of tests can be applied simultaneously or individually. 

Six Phases of Software Testing

Among these different types, there are many subcategories: usability testing, regression testing, exploratory testing, and sanity testing. Depending on the circumstances, each category serves a different purpose. Our next sections will discuss the STLC’s phases in more detail:

  • Requirement Analysis
  • Test Planning
  • Test Case Designing and Development
  • Test Environment Setup
  • Test Execution
  • Test Cycle Closure

Requirement Analysis

The software Testing Life Cycle begins with Requirement Analysis. During this phase, testing requirements are analyzed from a testing perspective to identify testable requirements. Communication is a key component in bridging the gap between the client’s requirements. Testing is tailored according to customer specifications by the Quality Assurance team.

Entry Criteria

  • Specification Documents and Application Architecture need to be provided.
  • It is necessary to clearly define the acceptance criteria as well as the availability of the above documents.

Requirement Analysis activities

  • Prioritizing and identifying requirements.
  • Analysis of feasibility and requirements through brainstorming sessions.
  • Prepare a list of questions for Client, Architect, Technical Lead, Business Analyst, etc.

Test Planning

With the information gathered in the previous requirement analysis phase, QA can plan ahead for testing. Planned testing is a crucial part of the Software Testing Life Cycle. During this phase, all testing strategies for testing the program are defined.

At this point, the Test Lead determines the entire project’s cost and effort estimates. Planning and strategizing test activities with resource analysis makes the planning phase more effective. The objective of the testing is achieved through it.

When performing automated testing, software testing cannot be valued without effective tools. This phase involves the selection of software testing tools. In the market, there are various tools available for performing software testing. Scalable testing is best achieved with cloud-based automation testing tools like LambdaTest.

Entry Criteria

  • A document that contains requirements.
  • An automation criteria report.

 Test Planning phase Activities

  • It describes the objectives and scope of the project.
  • Establishing a unique approach for each type of testing.
  • The roles and responsibilities are defined and assigned.
  • Locating the equipment and resources needed for testing.
  • Selecting the right testing tools.
  • Identifying the amount of time and effort required for testing.
  • Risk analysis.

Test Case Designing and Development

The QA team has examined the requirements and created a test plan based on them. Test plans are validated by creating test cases based on test specifications and strategy. 

The time has come to create and shape this test strategy into test cases. In the Software Testing Life Cycle, test cases are important in determining whether the product has defects. Defining the scope of functional and non-functional testing is the first step in designing the test cases. The process is also known as defect identification or defect analysis. Business Analysts can prepare this requirement document, containing all possible user scenarios. The test case design process will begin once we have the requirement document. After completing the Test Design step, QAS begins to write effective test cases. The first step is identifying all test cases covering all possible user scenarios. As the last step, we should remove any test cases unsuitable for execution due to their low priority or inability to identify defects.

Entry Criteria

  • The specifications documents.
  • Automated feasibility report.

Test Case Designing and Development Phase Activities

  • Test cases are developed, designed, and approved.
  • A review of existing test cases is conducted to determine whether they are pertinent, revised, and approved.
  • Automation scripts are written, reviewed, and approved if necessary.

Test Environment Setup

Developing test cases is followed by setting up and replicating ideal conditions and environmental factors. Hardware and software required to conduct software testing. In this phase, set up the testing environment. Evaluate software under certain parameters based on its test environment. As a stand-alone activity, it can run simultaneously with Test Case development. Organizations have different test environments. Developers or testers built some testing environments. A client may set up some test environments based on their needs.

While the testing team prepares the test environment, customers or developers prepare the smoke test. During smoke testing, evaluate the test environment for readiness and stability.

Entry Criteria

  • It is important to have a clear understanding of the test strategy.
  • Smoke test cases should be available at all times.
  • Results should be available for the tests.

Test Environment Setup phase Activities

  • Creation of test data.
  • Software and hardware necessary for testing have been identified and created in a test environment checklist.
  • Configure the test server and network.
  • An explanation and outline of the process for maintaining and managing test environments.
  • Conduct smoke tests to ensure readiness.

Test Execution

Quality assurance is capable of engaging in some practical testing activities. This phase involves executing test cases prepared in previous phases. It includes test cases, test data, and an appropriate testing environment. Each passed test case receives a score. An automated bug-tracking system notifies the development team when a test case fails.

Linked test cases can also prevent bugs from reoccurring. Failures in test cases would be associated with defects in an ideal world. When the development team resolves the bug, identical test cases are rerun to ensure they are working. Generate reports showing how many test cases have passed, failed, or were not run.

Entry Criteria

  • Testing strategy documents.
  • Test scenarios examples.
  • Test data

Test Execution Phase Activities

  • Execution of test plan and test cases.
  • Examining the differences between the expected and actual results.
  • Identifying the flaws.
  • Documenting the flaws and preparing bug reports.
  • Update the traceability matrix for requirements by mapping faults to test cases.
  • Performing a retest after a bug fixation.
  • Regression testing.
  • Keeping track of flaws until they are resolved.

Test Cycle Closure

A test closure phase begins after the test execution phase, and the completed software product is delivered. An evaluation of the entire cycle takes place in this phase. Additionally, characteristics of the testing process, such as quality attained, test coverage, test metrics, project cost, adherence to deadlines, etc., must also be considered.

In addition, the team evaluates the Software Testing Life Cycle to see what went well and what can be improved. A test case report determines the severity and issues of a test case. Metrics and closure reports are generated at the end of the test cycle.

Entry Criteria

  • Test case execution report.
  • A flaw report.
  • Executing the test cases should be completed.

Test Cycle Closure Phase Activities

  • Conduct a thorough review of the entire testing process.
  • There is a discussion regarding modified exit criteria, test plans, test cases, etc.
  • Analyzing and examining test results.
  • Testing deliverables, such as test plans, test strategies, and test cases, are collected and updated.
  • A test closure report and test metrics have been created.

A Comparison of SDLC and STLC

Software Development Life Cycle, or SDLC, is an essential part of software development. This phase involves developing a product and getting it ready for market. A critical part of the SDLC process is software testing. STLC is an acronym for Software Testing Life Cycle. 

The focus is on developing the product.The purpose of this program is to test products.
It helps in the development of high-quality software.It contributes to the defect-free development of software.
It is important to understand and meet the needs of users to create products that are beneficial for themAssuring that the product performs as intended by understanding its development requirements.
In SDLC, a development plan is created from requirements gathered by the business analyst.In STLC, test engineers analyze functional and non-functional requirements to develop a System Test Plan.
In SDLC, the development team creates a design plan at both a high and low level.In STLC, the integration test plan is created by the test analyst.
The SDLC collects requirements and creates features.In the STLC, tests are designed based on the requirements collected and checked against those requirements.
A complete SDLC cycle is completed before testing.The STLC phases begin after the SDLC phases have been completed.
The ultimate goal is to deliver a quality product that users can use.In the end, the goal is to discover bugs in the product and submit them for fixing to the development team.


The identification of faults in the last stage of the SDLC is no longer an effective approach. Taking too long to test and fix bugs can reduce your productivity. In the end, producing less will take longer. A smooth testing process requires efficient use of time and resources. You can fix bugs faster and improve quality by a systematic STLC.