Vijay Singh Khatri | 12 Dec, 2022

What is Software Testing Life Cycle?

Testing is integral to modern software development. Technically, software testing is an indispensable part of the software development life cycle i.e., SDLC. Although there are very many SDLC approaches, such as Agile, DevOps, and RAD, testing is omnipresent.

Interestingly, testing has its very own lifecycle, appropriately dubbed software testing life cycle. What does that suggest? It’s that software testing is a detailed and complex process.

Software Testing Life Cycle a.k.a. STLC helps in carrying out the testing process in a proper, thorough manner. It has many phases, such as requirements gathering, analysis, and execution. The following section comprehensively explores every phase of the STLC.

What is STLC? [Software Testing Life Cycle]

Software testing, like software development, involves several steps following a specific sequence. This is called the software testing life cycle or STLC. It defines the beginning, end, and in-between points of the complete software testing process.

Each phase of the STLC has certain deliverables, goals, and objectives. Although different testers can have a different approach to phases, such as combining one or more into one, iterating, etc. the main idea remains the same. Following are the various phases of a software testing life cycle:

1. Requirements Gathering

This phase marks the beginning of a software testing life cycle. During this phase, the testing team(s)/tester(s) engage in brainstorming sessions to check what features and parts of a software product are to be tested.

The requirements gathering phase identifies the scope of the entire testing endeavor. Some kind of mitigation strategy needs to be planned for features that aren’t testable.

2. Planning

Some STLC approaches either begin with this phase as the first phase or combine this phase with the requirements gathering phase to make a single, unified phase. The planning phase focuses on identifying all the activities and resources needed for fulfilling testing goals and objectives.

Identification of relevant metrics, as well as the approaches of collecting and tracking the same, are also done during the planning phase of the STLC. The planning phase is determined based on, usually, 3 things:

  • Requirements
  • Test strategy
  • Risk analysis or risk management and mitigation

3. Analysis

The “what” of the entire testing approach that the testing team(s)/tester(s) has built off so far is exploited in this STLC phase. One easy way of generating testing conditions is by analyzing the requirements. All this is done with leveraging:

Identifying the test conditions is not an easy job. You can find out all the apparent ones, but the ones, something like lurking variables, can restrain the team from finding out exactly and how aspects of the testing approach.

Important Factors Affecting the Identification of Test Conditions

  • The complexity of the software product.
  • Levels of testing.
  • Product and project risks.
  • Team(s)/Member(s) skillset.
  • The type of approach to SDLC.

There are so many other factors that affect the identification of test conditions, discussing them all is beyond the context of this write-up. As a rule of thumb:

  • Write detailed test conditions, to increase the coverage, and
  • Identify the exit criteria i.e., conditions when software testing must be stopped.

4. Design

Design is the software testing life cycle phase that is where it is defined how to test, once what is to be tested is figured out. This phase is a task made up of the following sub-tasks:

  • Breaking down the testing conditions into several smaller, sub-conditions for increasing coverage.
  • Creating requirement traceability metrics.
  • Creating test coverage metrics.
  • Identifying and gaining the test data.
  • Identifying and setting up the test environment.

5. Implementation

Once the testing team(s) has come up with the correct software testing approach while covering the how and what of it, it is time to implement the same. Detailed test cases are created during this STLC phase. It’s important to know here:

  • The priority of the test cases.
  • Identification of the test cases that will be part of the regression suite.
  • The correctness of the test cases.

When automation is involved:

  • Identify the candidate test cases,
  • Proceed with scripting the test cases, and
  • Review the test cases.

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6. Execution

This is where the actual execution of test cases takes place. Ensure that the entry criterion is met successfully before greenlighting execution. While executing the test cases, discrepancies occur as a non-desirable result. These can be logged in for reviewing later as defects. Track progress using traceability metrics.

7. Conclusion

The next phase in the software testing life cycle is the conclusion. It focuses on:

  • Exit criteria, and
  • Reporting.

Here, the reporting frequency of the test reports are decided by the testing team, with additional input from the stakeholders of a software project i.e., weekly (Weekly Status Reports a.k.a. WSR), twice in a week, biweekly, 15-day, or even daily (Daily Status Report a.k.a. DSR).

The more accustomed STLC project managers are to testing, the better they can benefit from technical information, such as defects raised, the severity of defects, and so on. Details about mitigating the defects are ample for reporting to non-technical stakeholders.

8. Closure

The last phase that wraps up the entire software testing life cycle includes:

  • Checking and grouping test cases based on their status i.e., executed or mitigated or some other.
  • Creating a document detailing,
    • What went well,
    • Scope of improvement(s),
    • What can be improved, how the same can be improved
  • Ensuring no top severity defects are open.

That sums up the entire software testing life cycle. Now, several types of testing are implemented when testing a software application. These tests are based on the size, scope, and mechanics of the software project under development.

Kinds of Software Testing

As stated, software testing is a detailed process. As such, there are numerous types of software testing. Each type of testing is designed to gauge some specific capabilities of a software product or an app.

For example, performance testing assesses some software products for performing certain tasks. Performance testing tools help in pinpointing performance issues with a software product that is under development.

By finding these issues, the same can be addressed that results in making the app/software project under consideration more performant. Here is a brief list of various testing approaches:

  • Alpha testing
  • Beta testing
  • Compatibility testing
  • Disaster recovery testing
  • Regression testing
  • Security testing
  • Stress testing
  • Unit testing

To make understanding various kinds of software testing easier, most of them can be classified under two categories:

1. Functional Testing

Tests under this group of software testing are also termed as functional tests. This type of software testing aims to assess the functional aspects of a software application. Primarily, the aim here is to check whether you’re getting the results you expected or not. Examples include:

    • Acceptance testing
    • End-to-end testing
    • Interface testing
    • Smoke testing

Such types of testing can be manual or with assistance from automation tools. JUnit and Selenium are two of the most popular functional testing tools.

2. Non-Functional Testing

Non-functional testing assesses the non-functional aspects of a software application, such as reliability and usability. Generally, non-functional tests follow functional tests.

Unlike functional testing, non-functional testing checks how well the software application is performing. Following are some of the popular forms of non-functional testing:

    • Failover testing
    • Load testing
    • Localization testing
    • Scalability testing

Usually, non-functional testing is manual.

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3. Maintenance Testing

Although some software testing teams consider maintainability testing in the non-functional group, some others like to keep it a separate testing type. As its name suggests, it tests a software product against maintainability i.e., how well can it be maintained.

While some vulnerabilities - in most cases, just a few - of a software application are apparent, most of them aren’t. This makes them more probable for exploitation. Therefore, a stringent testing regime is also important to ensure up the security standards of a software product.


Software testing assures the quality of a software product, whether it be a cross-platform project management application or a game or a video-sharing app or a cloud-based office tool or anything else.

Owing to the exponential growth in the software industry, learning software testing is surely beneficial. But before jumping in, remember, a software tester must be creative and experimental when it comes to designing tests and resolute when it comes to failures.

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By Vijay Singh Khatri

With 5+ years of experience across various tech stacks such as C, C++, PHP, Python, SQL, Angular, and AWS, Vijay has a bachelor's degree in computer science and a specialty in SEO and helps a lot of ed-tech giants with their organic marketing. Also, he persists in gaining knowledge of content marketing and SEO tools. He has worked with various analytics tools for over eight years.

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