What is software testing life cycle?

The main goal of the STLC is to identify and document any defects or issues in the software application as early as possible in the development process. This allows for issues to be addressed and resolved before the software is released to the public.

The stages of the STLC include Test Planning, Test Analysis, Test Design, Test Environment Setup, Test Execution, Test Closure, and Defect Retesting. Each of these stages includes specific activities and deliverables that help to ensure that the software is thoroughly tested and meets the requirements of the end users.

Overall, the STLC is an important process that helps to ensure the quality of software applications and provides a systematic approach to testing. It allows organizations to release high-quality software that meets the needs of their customers, ultimately leading to customer satisfaction and business success.

In the initial stages of STLC, while the software product or the application is being developed, the testing team analyzes and defines the scope of testing, entry and exit criteria, and also test cases. It helps to reduce the test cycle time and also enhances product quality. As soon as the development phase is over, the testing team is ready with test cases and starts the execution. This helps in finding bugs in the early phase.

1. Requirement Analysis: Requirement Analysis is the first step of the Software Testing Life Cycle (STLC). In this phase quality assurance team understands the requirements like what is to be tested. If anything is missing or not understandable then the quality assurance team meets with the stakeholders to better understand the detailed knowledge of requirements.

The activities that take place during the Requirement Analysis stage include:

Creating a requirement traceability matrix (RTM) to map requirements to test casesAt the end of this stage, the testing team should have a clear understanding of the software requirements and should have identified any potential issues that may impact the testing process. This will help to ensure that the testing process is focused on the most important areas of the software and that the testing team is able to deliver high-quality results.

2. Test Planning: Test Planning is the most efficient phase of the software testing life cycle where all testing plans are defined. In this phase manager of the testing, team calculates the estimated effort and cost for the testing work. This phase gets started once the requirement-gathering phase is completed.

The activities that take place during the Test Planning stage include:

At the end of this stage, the testing team should have a detailed plan for the testing activities that will be performed, and a clear understanding of the testing objectives, scope, and deliverables. This will help to ensure that the testing process is well-organized and that the testing team is able to deliver high-quality results.

3. Test Case Development: The test case development phase gets started once the test planning phase is completed. In this phase testing team notes down the detailed test cases. The testing team also prepares the required test data for the testing. When the test cases are prepared then they are reviewed by the quality assurance team.

The activities that take place during the Test Case Development stage include:

At the end of this stage, the testing team should have a set of comprehensive and accurate test cases that provide adequate coverage of the software or application. This will help to ensure that the testing process is thorough and that any potential issues are identified and addressed before the software is released.

4. Test Environment Setup: Test environment setup is a vital part of the STLC. Basically, the test environment decides the conditions on which software is tested. This is independent activity and can be started along with test case development. In this process, the testing team is not involved. either the developer or the customer creates the testing environment.

5. Test Execution: After the test case development and test environment setup test execution phase gets started. In this phase testing team starts executing test cases based on prepared test cases in the earlier step.

The activities that take place during the test execution stage of the Software Testing Life Cycle (STLC) include:

It is important to note that test execution is an iterative process and may need to be repeated multiple times until all identified defects are fixed and the software is deemed fit for release.

6. Test Closure: Test closure is the final stage of the Software Testing Life Cycle (STLC) where all testing-related activities are completed and documented. The main objective of the test closure stage is to ensure that all testing-related activities have been completed and that the software is ready for release.

At the end of the test closure stage, the testing team should have a clear understanding of the software’s quality and reliability, and any defects or issues that were identified during testing should have been resolved. The test closure stage also includes documenting the testing process and any lessons learned so that they can be used to improve future testing processes

Test closure is the final stage of the Software Testing Life Cycle (STLC) where all testing-related activities are completed and documented. The main activities that take place during the test closure stage include:

It is important to note that test closure is not just about documenting the testing process, but also about ensuring that all relevant information is shared and any lessons learned are captured for future reference. The goal of test closure is to ensure that the software is ready for release and that the testing process has been conducted in an organized and efficient manner.

Software testing is at the core of exceptional digital experiences. If you can’t sufficiently and thoroughly validate your products before customers use them, you risk alienating them. Software testing isn’t just a stage before release; it must be a multi-faceted, organization-wide, ongoing effort.

Just as there is a software development life cycle (SDLC) for developing digital products, there is a software testing life cycle (STLC) for validating them. Different members of the organization get involved at different stages to help businesses achieve their quality goals in a strategic, documented manner.

So, what is the software testing life cycle? We’ll provide an explanation of the process, as well as the individual STLC phases with examples.

The software testing life cycle is a sequence of tasks designed to understand the state of a system and make recommendations for improvement. The STLC involves strategizing, planning, executing and completing test cycles.

Traditionally, QA testing occurred shortly before product release as a way to ensure digital products don’t contain defects that negatively affect core functionality. However, as digital systems became more complex and businesses released batches of software and apps more often, the STLC evolved. In many organizations, testing no longer waits until a product is fully developed. Over the last couple of decades, some organizations have included STLC phases before and during development to maximize resources, employing some of the following tactics:

An effective STLC produces more comprehensive and valid results than a traditional post-development testing stage, helping organizations make changes that ultimately drive customer satisfaction and, thus, more revenue. The STLC process should be less a pre-release obligation than an effort to discover key insights that will benefit the business over the short- and long-term.

The software testing life cycle provides confidence in a software release. The STLC delivers that confidence through a series of tasks that take validation through ideation to design and execution. Each STLC phase is useful in its own way to achieve high-quality software releases. Likewise, each part of the STLC process comes with its own goals and deliverables, all intended to catch defects and optimize test coverage.

Let’s dig into these sequential phases of the software testing life cycle:

1. Requirement analysis

Most development initiatives begin with software requirements that specify what the business expects from the project. Software requirements often include high-level business needs, architectural requirements that detail how the feature will be designed and supported, and detailed system requirements from which developers build the product. System requirements include functional and non-functional specifications, both of which present opportunities to test and validate.

In this STLC phase, testers work both within their own teams and cross-functionally to contextualize how they will test the software. Requirement analysis often includes brainstorming sessions, identifying blind spots or unclear areas in the requirements, and prioritizing certain assessments.

When in doubt or lacking requirements documentation, the QA team will question the engineering or business side to clarify and calcify a testing strategy.

2. Test planning

The second STLC phase is important, as it guides much of the work to follow. Test planning takes the insights found during requirements or product analysis and turns them into a documented QA strategy.

The test team leadership determines what resources and efforts will evaluate the release. The resulting test plan documentation both informs testers and other departments how the testing work will commence, keeping everyone on the same page. This plan is especially helpful if other members of the organization will take part in testing and bug remediation, such as developers executing unit tests and writing hotfixes.

The test plan spells out several details of the QA work to be done, including the scope, objectives, types of functional and non-functional tests (both automated and manual), and details for the test environments. Once these details are determined, test management sets roles and timelines for the work. Finally, the testing team can determine what deliverables it will provide upon completion of the STLC phases.

3. Test case design and development

With the test plan in place, testers can begin to write and create detailed test cases. In this STLC phase, the QA team fleshes out the details of the structured tests they will run, including any test data they will need to facilitate those tests. While tests must ultimately validate the areas defined by requirements, testers can exert their skills and creativity in how they achieve this task.

When conceptualizing test cases, the tester’s goal should be to validate functionality within the allotted time and scope, especially core functionality. Test cases should be simple and well understood for any member of the team, but also unique from other test cases. Test cases should aim to achieve full coverage of the requirements in the specifications document — a traceability matrix can help track coverage. It’s important that test cases be identifiable and repeatable, as developers will add new functionality to the product over time, requiring tests to run again. They must also not alter the test environment for future tests, especially when validating configurations.

Test cases might also require maintenance or updates over time to validate both new and existing functionality. This work also occurs at this STLC stage.

Once test cases are ready, a test team lead or peer can review them. They might also review and update automated test scripts at this STLC stage. Ultimately, the team prioritizes and organizes these test cases into test suites that run later.

4. Test environment setup

The test environment provides the setting where the actual testing occurs. This is a crucial software testing life cycle phase, and it requires help from other members of the organization. Testers must have access to bug reporting capabilities, as well as the application architecture to support the product. Without these elements, testers might not be able to do their jobs.

Once ready, testers establish the parameters for the test environment, which include the hardware, software, test data, frameworks, configurations and network. In this STLC phase, testers adjust these environment parameters depending on what the test case requires. For example, the majority of a product’s users might be on an Android device, use a certain version of a Chrome browser and have a certain amount of processing power on those devices — these are parameters the test environment would include.

Smoke tests within these test environments provide a very early and rudimentary check that the software is ready for more comprehensive testing. These smoke tests against the builds are part of the deliverable in this STLC phase.

5. Test execution

Next in the software testing life cycle, it’s time to fully test the product. At this STLC stage, testers execute all of the test cases, or as many as is possible within the allotted time. QA professionals and automated scripts execute a number of functional and non-functional tests.

Here in the STLC, testers will identify and report detailed bugs that arise from test case execution and log the system’s performance compared to its requirements. As developers make fixes, testers often retest the product to make sure new defects don’t materialize. With all of these tests piling up in the test execution STLC phase, it’s important to make use of test automation where possible to achieve the test coverage and velocity you need.

6. Test cycle closure

The final STLC phase is test cycle closure. In this stage, the testing team provides a test closure report, which summarizes and communicates its findings with the rest of the team. This report typically includes summaries of the testing work and results, an assessment of the testing and the manager’s approval.

During the test cycle closure, the testing team checks its deliverables, which include details relevant to the testing work, such as the test strategy, test case documents, automated test scripts and test results. The team will then complete and close incident reports, which detail unusual or unexpected behavior that the test team observes during testing. The team must also archive the resources it used during testing, such as scripts, tools and environments, for later use.

From there, the organization plans the product for support and release, which often includes acceptance and feedback from customer representatives.

Communication is key in this STLC phase, as additional perspectives might uncover a quality, cost or coverage issue that the rest of the group missed. These discussions can yield additional analysis or inform how to improve QA work in the future.

The common software testing life cycle phases above follow a sequential approach similar to Waterfall application development. However, as many businesses rethink how they develop products, testing must also adapt to align with iterative organizational practices and pace of releases.

The QA team might follow an Agile testing method instead, which impacts the STLC phases above in various ways. Most notably, an Agile testing team might not file a report or an assessment of the testing work — the release would simply be planned for delivery.

Additionally, Agile testing places an emphasis on shift-left and shift-right testing to alleviate QA bottlenecks. While test automation is included in the STLC phases above, Agile testing might place a higher priority on methods like in-sprint testing and test-driven development, both of which generally result in cleaner, simpler bits of code. Production testing, or shift-right testing, helps the QA team identify defects after the test cycle closure. While these defects are often more costly to correct, it’s better late than never when it comes to fixing a bug. Shift-right often involves exploratory testing and user testing to find defects that test cases failed to uncover.

In short, the STLC phases above might change slightly depending on the organization’s development and testing philosophies.

There’s no time to spare when it comes to testing. The pressure to meet tight release deadlines is higher than ever. QA teams must look for any edge throughout the software testing life cycle that helps them release a high-quality product quickly.

Applause can be there with you from the very outset of the project as a strategic testing partner, genuinely invested in your company’s success. At any STLC phase, Applause can step in to provide the expertise of our world-class, worldwide community of experts and help you release exceptional products.

Testing with Applause opens up additional testing possibilities, such as testing on a broader range of devices and in different locations, which lets you focus on what to test, not how you will do it. From the very beginning of the STLC, Applause can pose important strategic QA questions to inform manual or automated QA strategy.

We’re flexible to your needs. Applause works where and how you need us. Once you determine testing priorities, we can help you determine the scope and timelines of the testing — or simply work within the ones you define.

• Requirement analysis.
• Test planning.
• Test case design and development.
• Test environment setup.
• Test execution.
• Test cycle closure.

The Software Testing Life Cycle (STLC) is a sequence of specific actions performed during the testing process to ensure that the software quality objectives are met. The STLC includes both verification and validation. Contrary to popular belief, software testing is not just a separate activity. It consists of a series of methodological activities to help certify your software product.

The STLC is a high-quality strategy directly associated with and part of the Software Development Life Cycle (SDLC), which in turn is a framework with 6 core principles:

In simple terms, the SDLC is a cycle where actions at each stage are reflected in subsequent stages.

The STLC also has its stages and most closely intersects with the SDLC at the fifth stage, which I’d describe below.

Since we can explain STLC as a set of testing measures, we can assume that it includes various stages, such as planning, control, implementation, standardization, and so on. All this leads us to the fact that the STLC is needed not only to test the developed product but also for the following:

As mentioned earlier, the Software Testing Life Cycle and the Software Development Life Cycle are closely related to each other, but they simultaneously pursue different tasks of the same goal, namely:

The overall goal is client satisfaction and achieving the highest possible score at the Verification and Validation stages.

The role of the STLC in the SDLC can be represented with a double line graph:

Where the SDLC and the STLC lines move in parallel for most of the project but begin to converge rapidly during the software development phase with deep synchronization during the SDLC Test phase. This graph is relevant to many different types of projects, not just large or independent ones, and will remain the same for the implementation of a task within a project and reverse for a project with a huge number of iterations (but in this case, the lines will diverge and converge more often).

The testing cycle is divided into different stages, and each has its own set of entry and exit criteria. The criteria are related to some activities and deliverables.

A collection of conditions or goals that must be met to create an appropriate and favourable testing environment are known as entry criteria. Entry criteria, which are finalised and chosen after a comprehensive analysis of the software and business requirements, guarantee the accuracy of the testing process, and ignoring them can lower the process’s quality.

The exit criteria describe all of the requirements that must be met before testing in a particular phase can be completed. All deliverables should be finished in order to satisfy the exit criteria. There should be no flaws, mistakes, or bugs, and all high intensity and high priority mistakes have been corrected.

The STLC has several interconnected phases and is generally very similar to the SDLC system. These phases are sequential and are called:

Let’s take a closer look at each of them.

Requirements analysis is one of the most important phases because this is when you can fix project flaws almost completely free of charge. The requirements analysis phase also identifies the potential need for automated testing and allows making economic calculations of labor costs based on the project estimation. This is also when the Entry Criteria and the Exit Criteria are discussed and documented.

Entry and Exit Criteria in software testing are necessary for all levels of the STLC. Entry Criteria define the prerequisites that must be met before you start the testing, while Exit Criteria define the prerequisites for concluding it. Ideally, you don’t proceed to the next testing stage until every Exit Criterion for the previous one is met.

Now imagine that an edtech startup company is developing an online learning platform for K-12 students to be launched in six months. The platform will include various types of educational content, such as videos, quizzes, and interactive exercises, and will be accessible on desktop and mobile devices.

The edtech startup conducts market research and user surveys to identify the target audience and their preferences and needs. They discover that the majority of K-12 students prefer interactive and gamified content, and that teachers prefer content that aligns with their curriculum standards and provides analytics and progress tracking features.

Based on these findings, the company defines the requirements for the platform, including content types, curriculum standards, and the user interface and experience. For example, they decide to include animated videos, quiz games, and virtual labs, and to align them with the common core standards in science and math. They also design the user interface to be intuitive and engaging, with colorful graphics and sound effects, and to include features for tracking progress, communicating with teachers, and accessing learning resources.

At this phase, a test plan is formed. This is the concretization of all phases of the testing itself, timing, participants, and responsibilities. As a result of this, we receive data on:

Back to our example, this is when the testing team reviews the requirements and defines the testing objectives, strategies, and criteria. They decide to focus on functional, usability, and performance testing, and to use both manual and automated testing approaches.

They identify the testing types, such as functional, usability, performance, security, and accessibility testing, and plan the testing schedule, resources, and tools. For example, they decide to use JIRA for test case management, Selenium for automation testing, and LoadRunner for performance testing. They also allocate specific testing tasks to individual team members and set up regular testing meetings and checkpoints.

They also set the quality goals and metrics to track and measure the testing progress and results. For example, they set a goal of achieving a 95% pass rate for functional testing, a 80% satisfaction rate for usability testing, and a 3-second load time for each page.

Test development implies using manual and automated testing to achieve full coverage of the software’s functionality and features, with the process being based on the requirements set up beforehand. More often than not, the test cases carried out using testing automation are written separately, since the cases for manual testing are described in the form of cheat sheets. Each has its own Test Case Life Cycle, which encompasses its creation, verification, and rework.

The testing team from our example creates test cases for each testing type, based on the requirements and the testing objectives. For example, they create test cases for each type of interactive content, such as videos, quizzes, and labs, and test them for functionality, usability, and performance.

They design the test scenarios, inputs, expected outputs, and the test environment and data needed for each test case. For example, they create different scenarios for a quiz game, such as single-player mode, multiplayer mode, and time-limited mode, and test them with different input parameters and expected outcomes. They also create a test environment that simulates different user devices and networks, such as desktop, mobile, and 3G, and test the platform under various conditions.

They also develop the test scripts and automate the testing process wherever possible to increase efficiency and reduce manual effort. For example, they use Selenium to create automated scripts for regression testing, and to test the functionality and compatibility of the platform with different web browsers and operating systems.

The test plan makes it clear which test environment should be used. At this STLC phase, operating systems and virtual machines are configured, testing tools like Selenium, Katalon Studio, and the project’s test environment and databases are deployed. We also make requests to DevOps and Admins if support is needed.

In our example, the testing team sets up the test environment, which includes the hardware, software, network, and data needed for testing. For instance, they set up a testing server that replicates the production environment, and install the necessary software and drivers for the testing tools and frameworks used.

They also configure the testing tools and integrate them with the development environment to enable continuous testing and feedback. For example, they use JIRA to track defects and issues, and to link them to specific test cases and requirements. They also use Jenkins to automate the testing process and to trigger alerts and notifications for failed tests.

Tests are performed based on ready-made test documentation and a correctly configured test environment. All test results are recorded in the Test Management System. Negatively passed tests, where the actual result differs from the one expected, are recorded as errors and transferred to the development team for script revision with subsequent rechecking after correction.

The testing team from the example executes the test cases according to the testing plan and the testing schedule. Let’s say they conduct functional testing first, then usability testing, and finally performance testing. They analyze the test results, identify defects and issues, and report them to the development team for resolution. In the end, they find that some quiz questions are not displayed properly.

The last phase of the STLC is the final generation of testing reports for the client. These should include the time spent, the percentage of defects found to positive test results, the total number of errors found and fixed. As far as the testing department is concerned, this is the moment for analyzing its work, summing up the results, analyzing its productivity, and the opportunity to make suggestions for improving the quality of testing.

And the final part of our example. The development team fixes the defects and issues reported by the testing team, and re-runs the relevant test cases to verify the fixes. They modify the quiz code to correctly display the questions, and re-test it with the same test cases as before.

The testing team then conducts a final regression testing to ensure that the fixes have not introduced any new defects, and that the platform meets the quality goals and metrics set earlier. They run all the test cases again, including the ones that were previously failed or blocked, and check if they all pass this time.

Once that is done, the testing team generates a test summary report, which includes all the testing activities, their results, and recommendations, and presents it to the management and stakeholders. The report can summarize the test execution and results for each testing type, and provide suggestions for further improvements and enhancements.

Finally, the edtech startup company launches the platform to the market and monitors its performance and feedback from users and teachers. They also plan for the next testing cycle, which includes new features and updates based on the user feedback and market trends. For example, they may want to add a new feature for personalized learning paths, and plan for a new testing cycle with the new functionality in mind.

The example above is a sort of perfect scenario for the software testing lifecycle. But sometimes there are situations when variations in  STLC are unavoidable. Let’s look at some possible cases where these variations can take place.

In an Agile environment, the testing process may not follow the standard STLC sequence, which is designed for Waterfall development. Agile development emphasizes flexibility, iteration, and quick feedback, so testing is often done in parallel with development rather than in sequential stages. Test planning, case development, and execution may all happen simultaneously with development sprints, and the cycle may be more fluid and iterative.

In some cases, a software application may require an emergency patch or hotfix to fix a critical issue. In such cases, the standard STLC sequence may need to be compressed or bypassed to quickly deliver the fix. For example, the test planning and case development phases may be skipped, and the testing team may need to focus solely on executing pre-existing test cases to confirm that the patch has resolved the issue.

In an organization with legacy systems, the STLC sequence may not be followed strictly due to the technical constraints of the older systems. The environment setup phase, in particular, may be difficult or impossible to complete, as the legacy systems may not be compatible with modern testing tools and techniques. In such cases, the testing team may need to rely on manual testing or older testing tools, which may require a different approach to the testing process as a whole.

If an organization outsources its testing to a third-party vendor, the testing process may not follow the standard STLC sequence. The vendor may have its own testing methodologies and tools, which may differ from the organization’s standard approach. The vendor may also need to adapt the testing process to accommodate differences in infrastructure, culture, and communication channels between the vendor and the organization. In such cases, the organization may need to establish clear expectations and guidelines for the testing process to ensure that the vendor’s approach aligns with the organization’s quality standards.

In a DevOps environment, testing may be automated and integrated into the development process through continuous testing. Continuous testing involves running automated tests on every code change, commit, or build to detect defects and regressions as early as possible in the development cycle. Continuous testing may blur the lines between the different phases of the STLC and require a different approach to test planning, case development, and execution. In such cases, the testing team may need to focus on creating reusable automated tests and ensuring that the testing process is integrated seamlessly into the development pipeline.

Test automation is the best way to improve the effectiveness, efficiency, and coverage of your software testing. An automated testing tool can run pre-recorded and predefined actions, compare the results to expected behaviour, and report the result of these manual tests to a test engineer. Once automated tests are created, they can be readily repeated and extended to accomplish tasks that manual testing cannot. As a result, automated software testing has emerged as a critical component of successful development projects.

Benefits of automated testing:

Parallel testing is some kind of opposite to sequential testing. Parallel testing is an automated test process that allows developers and testers to run multiple tests against various real device variations and browser configurations at the same time. Parallel testing aims to address time constraints by spreading tests equally throughout the resources available.

For example, if 20 test cases take 100 minutes to complete, 10 parallel operations could run 2 test cases each, reducing total testing time to 10 minutes. If you have enough resources, say 20 real mobile devices and browsers for parallel execution of 20 test cases, you should be able to greatly reduce the runtime to 5 minutes.

Benefits of parallel testing:

Now that we know what the STLC in software testing is and what it is for, we can say what the graph of interaction between the STLC and the SDLC will look like with full certainty:

Software Testing Life Cycle (STLC) is a process used to test software and ensure that quality standards are met. Tests are carried out systematically over several phases. During product development, phases of the STLC may be performed multiple times until a product is deemed suitable for release.