How Important is the Software Testing Life Cycle (STLC) in QA?

We use software almost every day and we are used to relying on it. Even if we don't notice this, the software has surrounded us in our daily life for the past few decades. We use the software at school, in hospitals, at home, while working from the office, and then driving back home. Software now takes the part in the tasks we used to do ourselves and has made our lives significantly easier.

However, all this software needs to be accurate and tested prior to release to the public. Therefore, it's dangerous to underestimate the meaning of software testing methods. 

This is what controls the quality and reliability of the software we use in our daily lives. And if you provide customers with software products, quality assurance and product testing are the bare minimum.

The Software Testing Life Cycle assures that the created software performs as expected and was designed from the beginning. Ignoring this stage means staying behind competitors. Already 42.5% of companies indicate that test automation is a key part of QA. 

This article is a continuation of our software development life cycle text (SDLC) and provides you with valuable and needed knowledge about the software testing life cycle.

What is Software Testing Life Cycle (STLC)?

Under STLC we mean the Software Testing Life Cycle, which is a continuous process of Quality Assurance (QA). The STLC is performed to make sure that software quality requirements are met. Also, STLC is an act of validation and verification. During the software testing life cycle, the QA team tests multiple software artefacts to find any defects and ensure the best application quality possible.

Usually, the software testing life cycle takes up to six steps, depending on the project. Each step could be performed by different teams to achieve software testing goals. Some of these steps can be omitted, like the sixth stage. Let's have a closer look at all STLC stages.

The common question about STLC is what makes it different from SDLC (Software Development Life Cycle).

If we sum up the software testing life cycle, we have to mention that it's a complex process with different stages, and here we explain every step of STLC below. 

Six stages of Software testing life cycle

What are the Entry and Exit criteria?

Entry criteria are a list or description of requirements for every testing step. Those requirements should be met before the QA team and testers can run the test.

Exit criteria are set during the Test Planning stage and are part of the final test plan. In brief, exit criteria mean the accordance between the test cases' goals and their achievement.

All testing stages that are described below have their own Entry and Exit criteria.

Requirement Analysis

Knowing what or how you have to perform STLC is crucial for the result. The Requirement Analysis phase is a unique chance to find the requirements that don't match the team's resources. This is also a step when it's easier to change clients' unrealistic requirements and help them understand how to make their software needs achievable. Plus, it's a phase when Exit and Entry Criteria are set.

Requirement Analysis is a business-oriented step of the software testing life cycle too. Sometimes STLC needs automated testing, which cost is better to be included in the project estimate from the very beginning.

Test Planning

It's a step that is taken before the actual testing begins. And the result of planning is a clear understanding of the testing strategy. The person in charge of the Test Planning stage is a Quality Assurance Manager.

This team member creates a Test Plan Document, selects and sets the testing toolkit according to the requirements, estimates test effort, and sets testing requirements. Of course, all the potential risks are also analysed during the Test Planning stage.

Test Case Development

It's a stage when the QA team writes the test cases for every unit. This step is performed according to documents written during the Test Planning stage. Also, the QA team takes other crucial actions in this phase. For example, a user's possible activities, working on test conditions and verifying test cases according to modifications. At the end of this step, the team has a test case development plan, test data, and a test automation script.

Test Environment Setup

It's a stage that can be run along with the Test Development step. The test environment is better tested with a smoke test to check if this environment is stable. It's an important step to ensure that the Test Environment will effectively reproduce the product environment.

Test Execution

It's a step when the test cases are finally performed. Then, the testing team communicates with the developers' team and gives them feedback on reported bugs. Bug reports usually have a settled format that makes the developers' and testers' work more accessible. The critical test execution step is secondary testing after fixing previously reported bugs.

Test Cycle Closure

And finally, the last step of the Software Testing Life Cycle. In brief, the test cycle closure is a process of summing up what worked for the tested project and what didn't work. The result is the completed Test Closure report and prepared Test Metrics.

Types of tests in software testing

Alpha testing

This software testing is usually performed on the stage when the final product is almost completed and ready to launch. The focus during the testing process is on the users' behaviour. Alpha Testing is run by the testing team. Some test cases are given to the development team, and even other company employees. The result of the Alpha Testing is a bug-free software build created after meeting the requirements and users' feedback.

Beta testing

Unlike Alpha testing, Beta tests run in the user's environment. It is the last stage before launching the software to the actual end users. During this phase of beta tests, testers check the products' usability, security, functionality, and reliability. In addition, beta testing provides the chance to get to know the users' feedback after usage and adjust according to customers' needs.

Compatibility testing

This is performed to test if the developed software is compatible with computer components. This non-functional test helps to check how an application works across different operating systems, browsers, hardware, network, and devices.

Disaster recovery testing

This test's goal is to check how the system will behave after a service disruption. Ideally, the data should be easily restored, and the software has to continue operations even after a service disruption.

Regression testing

It is a re-run test that helps to check if already developed and tested software works after recent changes. If it's not working, this process is claimed as regression and requires additional work on the product. Regression testing could be both functional and non-functional.

Security testing

This test measures the vulnerability of the tested software. Testers in the QA team use this method to find and report all the potential security issues within the product according to the requirements of safety standards. Secure software protects businesses' good reputations and provides users with a safe user experience.

Stress testing

This test type helps check the software's ability to work under an intense load. Stress testing is essential for critical infrastructure software of industries like healthcare and communication. It is crucial to understand whether or not the software can stand the maximal pressure.

Unit testing

This method helps to test the smallest parts of the software product that could be tested. It runs manually or automatically, depending on the project's needs, budget, and testers' qualifications. This test covers metrics like build quality, test pass %, code coverage %, defect rate, test execution coverage %, cyclomatic complexity, and defects by priority.

Defect Life Cycle

Defects are commonly called `bugs`. All bugs that are in the software will affect its work at some point in time. No matter how big or small these bugs are, the final users of the software will get a worse user experience with your project.

The point of Software Testing is finding and reporting those bugs. And we are genuinely convinced that it's essential to understand what a bug is and how it behaves.

What the bugs' life cycle looks like.

Why is STLC important for the SDLC?

In our previous articles, we described the Software Development Life Cycle (SDLC). STLC is a crucial and irreplaceable part of this process. Among the reasons we have to mention, here are some of the more important reasons we want to cover.

Thanks to STLC, the product turns out to be more predictable. The customers get what they expect and have a better user experience with a well-tested product. Besides, investing in STLC makes the software way safer and more stable.

Early-found bugs are cheaper to fix. So, STLC helps businesses to save money and time that could be spent on fixing defects and rebuilding the system they damaged.

A clear and unified testing process allows different teams to perform adequate testing multiple times, with predictable results.

STLC minimises human errors' role in the software development life cycle process. No matter how good we are at our jobs, we can make mistakes from time to time. However, in tech, even a small mistake can lead to software inability.