How to Optimize Software Testing Life Cycle – The Full Guide

If you’ve noticed that your development costs are higher than you initially anticipated, or it takes longer to release new products, it may very well be a sign that your testing cycle needs optimization. The Software Testing Life Cycle (STLC) is a crucial component of modern development processes, and optimizing it can help address a number of issues, from lowering the cost of software development and speeding up time to market to enhancing the overall quality of your product.

If this is something you’ve been thinking about, don’t look further. In this article, we’ll discuss the key stages of software testing, methodologies, best optimization methods, and strategies that can help you streamline your test life cycle. Let’s dive into it!

Key Takeaways

1. Software Testing Life Cycle is a sequence of verification activities carried out along development to ensure the product under test isn’t flawed and meets the established requirements and objectives. 
2. STLC performs a few important roles: checking the code or application for bugs or simulating an application to perform a certain operation. 
3. The typical STLC comprises six software testing phases, including requirement analysis, test planning, test case development, test environment setup, test execution, and test cycle closure. 
4. Integrating STLC into the software development process offers numerous advantages, from enhanced product quality and user loyalty to reduced bugs and development costs.
5. One of the biggest challenges in STLC is ensuring that the team has all the required resources and tools needed for comprehensive testing. In some cases, when the team doesn’t have required expertise or tools, outsourcing testing activities can be the most cost-effective solution.
6. The number and sequence of testing phases in STLC may slightly vary depending on whether you stick to Waterfall or Agile methodologies. 

What Is Software Testing Life Cycle (STLC)?

The software testing life cycle (STLC) is a sequence of verification and validation activities carried out in the course of software development to ensure that the software under test is functioning properly and aligns with the requirements set out before the development team. This process is iterative and collaborative and is essential to the development and release of high-quality software. During the life cycle, QA engineers may use a variety of tests alongside each other, including:

• Unit testing;
• Regression testing;
• Exploratory testing,
• Parallel testing;
• Performance testing;
• Automation testing, and more.

STLC is adaptable and flexible, which means testers can choose and combine these testing methods depending on the requirements and goals of the project. Ultimately, this allows companies to maintain a high level of software quality while efficiently managing development and testing resources. 

STLC vs SDLC: What Is the Difference? 

Although these terms may seem very similar, they are not. The Software Development Life Cycle (simply abbreviated as SDLC) is a systematic approach to software development that includes all the phases and activities required to build a software product. On the other hand, the software testing lifecycle is a subset of the SDLC process. It focuses specifically on testing a software product and accompanies the development of software throughout all of its stages.

Below, we outline the main differences between these two processes so you can better understand how they are approached.

In general, while SDLC is a comprehensive software development process, STLC is responsible for creating a test plan to evaluate and ensure software quality using various testing tools. Both processes are important for delivering successful software, but they serve different purposes.  

The Role of Software Testing Life Cycle in SDLC

As we’ve just mentioned, STLC and SDLC aren’t the same thing, even though they are very closely related. The main difference between the two is the tasks they pursue. For SDLC, it’s all about gathering technical requirements and wrapping them into a product with functionality discussed in the pre-development phase. 

When it comes to STLC, it performs several roles. One of them is to ensure that the requirements discussed in the initial stages of the product development are met. Another one is to test the code or application for errors, ensuring no bugs slip into the implemented functionality. Furthermore, testing plays a vital role in simulating an application to perform a certain operation.

While not all projects require testing right from the beginning, most often both cycles run in parallel, with STLC deeply synchronized with SDLC in the development phase. Even if the project requires lots of iterations, the process of continuous testing ensures that each iteration is validated against the requirements and expected outcomes. This synchronization between STLC and SDLC allows for early detection of bugs, making it easier to address them before they escalate and become too expensive to fix. 

Entry and Exit Criteria

Most likely, you’ve heard about entry and exit criteria in STLC. However, since some people confuse these terms, we’re going to quickly explain them. 

In essence, everything is as simple as it sounds. Entry criteria are certain conditions that must be met before entering a specific testing phase, while exit criteria define the conditions that must be satisfied for a testing phase to conclude. 

For example, entry criteria may include identifying requirements for testing, setting up the required test environments, and having a documented test plan. Conversely, exit criteria require certain actions to signal the completion of the software testing phase, which could be defect reports, updates on test results, certain test metrics, etc.

Ideally, one phase should replace another one only when the previous one comes to an end, but in the imperfect world that we live in, this doesn’t always happen. Regardless, understanding these checkpoints is important for maintaining testing structure and effectively managing test risks.

Further down, we’ll take a look at the important software testing stages, along with their entry and exit criteria. 

The 6 Phases of Testing 

It’s time to finally dive deep into the software testing phases. In general, there are six phases of the software test life cycle. However, this number may vary depending on the chosen methodology (we’ll get there later in the article). Also, it may vary based on the complexity of the project itself. For example, if your website was created solely for the purpose of marketing activities, it may not need to go through all the testing life cycle phases. In most cases, it will be enough to test it only partially. On the other hand, if it’s a banking app we’re talking about, thorough testing is a must. 

So, here are the important software testing steps QA engineers should perform: 

1. Requirement Analysis

The first step in the software testing life cycle is requirement analysis. During this stage, QA engineers closely collaborate with their own department as well as other key members of the team. The goal of this collaboration is to study business objectives, features to be designed and supported, and stakeholder requirements, including functional and non-functional specifications. In case there are certain questions or doubts left, they may seek clarification from the tech and business specialists of the project.

Entry Criteria:

• Defining the types of tests to be performed;
• Choosing test environments;
• Gathering information about the development and testing priorities;
• Preparing the RTM (Requirement Traceability Matrix) document for the project;
• Carrying out a feasibility analysis for test automation (in case the QA team decides to automate certain tests).

Exit Criteria:

• Creation of the RTM and test strategy;
• Approval of the test automation feasibility report. 

2. Test Planning

In the second STLC phase, the QA team assesses the resources and effort needed to carry out the project based on the data collected and processed in the requirement analysis phase. The key objective of this phase is to provide the project team with documentation, outlining the organization, approach, and execution of testing throughout the project, including the testing schedule and possible test limitations.

Entry Criteria:

• Defining requirements and scope of the project;
• Developing a test strategy;
• Determining roles and responsibilities;
• Preparing hardware and software requirements for the test environment;
• Preparing documentation necessary to launch the project.

Exit Criteria:

• Finalizing allocation of resources and test plan document;
• Approval of the test strategy document and test plan.

3. Test Case Development

With a solid test plan and strategy in place, the team can move on to the next step — the design and development process. This phase involves the creation, verification, and rework of test cases and test automation scripts based on the data from the test plan. The team is also preparing test data to flesh out the details of the structured tests they will run. All test cases and scripts created in this phase will be continuously maintained and updated over time to test new and existing features.

Entry Criteria:

• Creating test cases and test automation scripts (in case the QA team decides to automate certain tests);
• Reviewing and writing test cases and test automation scripts;
• Creating test data.

Exit Criteria:

• Developing and approving test cases, test data, and test automation scripts;
• Finalizing test design document.

4. Test Environment Setup

The purpose of the test environment stage is:

• To provide the QA team with a setting where they can exercise new and changed code, provided by the development team;
• To locate possible faults and errors; 
• To contact the responsible developer, providing them with a detailed test report. 

Different types of testing require distinct types of test environments, and the choice of testing methods is directly linked to their complexity. In some cases, tests can be run sequentially, while in others, they may need to be run in parallel (some or all at once). 

When setting up a test environment, the QA team considers a whole range of parameters, such as hardware, software, frameworks, test data, and network configurations, to name a few. These parameters are then adjusted depending on a particular test case.

Entry Criteria:

• Setting up the test environment;
• Trying it out by conducting a series of smoke tests.

Exit Criteria:

• Test environment is all set up and ready to go.

5. Test Execution

The next part of the STLC process is the testing itself. At this stage, the QA team executes all of the test cases and test automation scripts they have prepared in test environments. The software testing process includes all kinds of functional and non-functional tests, during which software testers identify bugs and provide detailed testing reports to the project team. After developers make the necessary fixes, the QA team runs a series of retests to make sure that all detected defects are fixed.

Entry Criteria:

• Carrying out test cases based on the testing strategy documents;
• Recording test results and metrics;
• Re-testing fixes provided by the development team;
• Tracking every log defect and error until they are resolved.

Exit Criteria:

• Detailing testing reports;
• Updating test results;
• Completing the RTM with execution status.

6. Test Cycle Closure

The final stage of the software testing life cycle phases involves several test activities, such as collecting test metrics and completing test reports. The QA team summarizes the results of their work in a test closure report, providing data on the types of testing performed, processes followed, the number of test cycles carried out, etc. This document ends the STLC life cycle.

Entry Criteria:

• Assessing the cycle completion;
• Preparing test metrics;
• Preparing a detailed test closure report. 

Exit Criteria:

• Preparation and approval of the test closure report.

To better understand how this works, we’ve compiled a table that visually outlines key stages of the STLC along with their entry and exit criteria.

From this point on, the project team strategizes for the application’s support and release. This includes analyzing all the testing artifacts and building a test strategy for the application’s further growth and expansion.

Benefits of Software Testing Life Cycle

Planning testing ahead offers a number of benefits that directly impact the overall success of the project. With a well-defined SDLC, teams achieve better effectiveness, reduce the number of unforeseen errors, and go in line with the established timeframe. Here are some more important benefits highlighting the importance of the STLC:

Improved software quality

The main goal of the STLC is to catch and mitigate bugs early in development, preventing them from escalating into major issues later on. This proactive approach ensures a higher-quality product, with fewer defects making it to the production stage.

Enhanced user experience

By addressing problems before they become ingrained in the system, teams can mitigate faults on the user side and provide a higher-quality product with user-friendly and glitch-free features. This, in turn, can lead to a better user experience, ultimately making your product more attractive and competitive in the market. 

Effective risk mitigation

A thorough testing at an early stage allows teams to identify potential issues and vulnerabilities that may arise during development and take the right measures to prevent them. As a result, many of the bottlenecks that could have led to delays and costly rework at the later stages can be effectively mitigated.

Reduced costs

Fixing bugs early in development is a lot cheaper than in the production stage. For example, the cost of a bug fix in the planning stage is typically around $100, but if the same bug is found only in the production stage, the cost can skyrocket to $10,000 and even more. The problem with bugs is that they tend to snowball – if you miss something in the early phases, it can lead to a series of cascading issues that are far more difficult and expensive to resolve later on.

Streamlined communication

Integrating testing into development has a positive impact on overall communication within the team. Active participation of testers in the process along with developers and other stakeholders ensures that everyone is on the same page regarding requirements, potential risks, and progress and that they are moving forward in the right direction.

Smooth deployment

Finally, testing the product throughout the development process ensures that all the features implemented in the product function smoothly and the product is ready for release without any last-minute surprises. This not only gives you confidence that the product is aligned with user expectations, stable, and bug-free, but also speeds up time to market. 

STLC Challenges

Testing software products comes with its own set of challenges that can impact both the testing process and the overall project success. Let’s explore some of the most common challenges faced by QA teams to better understand how to navigate them.

Time constraints

Testing often gets squeezed into tight schedules, leaving limited time for thorough quality assurance. When deadlines are looming, teams may be forced to cut corners on testing, leading to missed bugs and potential problems down the line. If you don’t want to be in a position where you have to choose between fast delivery and quality, it’s vital to allocate enough time for testing in the planning stage when estimating the project timeline.  

Resource constraints

As products become more complex and advanced, it is essential to have both a skilled team and an extensive testing infrastructure. Without having a comprehensive set of tools, carrying out a full STLC becomes challenging (if not impossible). With this in mind, you should invest in the tools and technologies to support your testing efforts from the get-go. It can also be a good idea to outsource some activities from remote QA teams to overcome resource limitations. 

Complex integration testing

Most products today involve multiple integrations with APIs and third-party systems. One feature might depend on various external services, each with its own set of requirements and potential points of failure, making testing these integrations highly complex. To manage this complexity, you can break down tasks into smaller modules. Furthermore, many specialized testing tools like Postman, SoapUI, and Apache JMeter are designed to help with testing complex system architectures. 

Evolving technologies

Testing, just like everything, keeps evolving all the time. Many new tools and methodologies are emerging, so it’s important for teams to stay on top of trends and integrate the best of them into their workflow. By encouraging your QA engineers to continually learn and attend training programs, you ensure that they stay up to date with the latest techniques and tools, and that their testing strategies are on the cutting edge.

Software Development Methodologies and the STLC Life Cycle

As we’ve mentioned earlier, STLC may have various phases of testing based on the methodology used. Let’s talk about it in detail by taking a closer look at the two most popular models — Waterfall and agile. 

Waterfall Methodology 

The Waterfall model is the oldest and most popular methodology used. You’d be surprised but even now, over 56% of companies follow this model to create software products, which shows that it’s still widely adopted across a vast number of projects. 

The beauty of the Waterfall model is its simplicity and linear approach. Every phase here strictly follows one after the other, providing a great level of predictability. However, the flipside of the coin is that it is rather difficult to go back if any issues are discovered at later stages. Therefore, it’s best suited for short-term projects with well-defined requirements. 

The typical software testing life cycle in this model consists of the following phases:

1. Requirement analysis. In the Waterfall model, the testing phase begins after the development phase is completed. The testing team is focused entirely on gathering and analyzing the requirements to ensure they are clear, complete, and testable. 
2. System design. During the next stage, QA engineers work on creating detailed test design documents and test cases that meet the specifications of the software design. 
3. Implementation. Further on, the team works on refining and finalizing test cases, which is an important step for the next stage where the code is completed and it’s time to test the product.
4. Testing. This phase includes unit testing, integration testing, system testing, and user acceptance testing, each of which verifies different aspects of the software quality.
5. Deployment. Once testing is successful, the software is deployed into the production environment. 
6. Maintenance. The last stage is maintenance. This is an ongoing process, during which developers deal with any post-production issues or necessary enhancements. The QA team may need to retest the software a few times until the detected issues are resolved. 

Agile Methodology

Agile has emerged as an alternative to the Waterfall model. It addresses its limitations, offering a flexible and iterative approach to software development. According to surveys, at least 71% of businesses in the USA are adopting agile, while 29% of organizations have already been using this methodology for 1-2 years. 

Agile offers a lot of advantages that have played a crucial role in its widespread adoption. The most important of them is the ability to quickly respond to market changes and fix bugs on the spot, eliminating costly rework at the last stage of an SDLC. Besides, since agile encourages incremental development, it significantly accelerates time-to-market, allowing companies to gain a competitive advantage in the market. 

Let’s look at the testing procedure in agile development:

1. Planning. Like any testing, agile testing begins with planning. However, unlike the Waterfall model, in agile, the planning is more dynamic and iterative. The team prepares test plans in sprints, collaboratively defining user stories or features to be tested in the upcoming iteration. 

1. Test design. Test design in agile is carried out simultaneously with development. The testing team creates test cases and acceptance criteria as features and user stories are being developed. 
2. Testing. Various types of testing, such as usability testing, exploratory testing, and regression testing, are executed throughout the STLC in agile to ensure software quality. Each of them has its own purpose and is executed in different testing scenarios.  
3. Deployment. Agile projects often employ CI/CD practices, allowing for automated testing and quick deployment of new features. This minimizes the risk of defects at later stages and speeds up product launches. 
4. Review. The next step is the review stage, where the QA team evaluates the results and designs strategies to improve the development and testing processes.
5. Launch. Finally, testers and developers plan for the release of the product. They decide which features and user stories are going to be included in the release and what necessary testing activities must be completed to ensure the product meets the requirements. 

To summarize, the distinct difference between the Waterfall and agile models is that in agile, testing isn’t a separate phase but an integral part of the development process that is performed continuously throughout the project, right up to the launch. Conversely, in the Waterfall model, testing is run as a sequential phase that begins only after development is complete. Other than that, the testing life cycle follows pretty much the same flow.

Best Practices to Improve the Software Test Cycle

Now that we’ve covered the essential phases of testing and their activities and deliverables, as well as the specifics related to the software methodology used, it’s time to move on to the best practices that can help you optimize your software test cycle. By optimizing your testing stages, you can achieve significant improvements in your flow, from reduced time-to-market and quicker launches in upcoming releases to improved software quality overall. 

Start With a Testing Strategy

One of the first steps to achieving a successful STCL is defining a testing strategy. The strategy should outline the scope of testing, budgets available, testing deadlines, and testing objectives. To help you create a well-defined test strategy, consult with all stakeholders, developers, and QA engineers on the team.

Develop Test Plans

Once the strategy is formed, the next step is to create a test plan. Unlike the strategy, test plans are live documents that should be regularly reviewed and updated. Typically, a test plan covers:

• Project description;
• Test strategy and approach;
• Features/parts in scope;
• Features/parts out of scope;
• Test environment description;
• Specific testing activities;
• Resources; 
• Schedules; 
• Deliverables; 
• Team roles and responsibilities; 
• Pass and fail criteria. 

During this stage, it’s also necessary to specify and configure test environments and devices, and define which tools will be used. Most often, teams use testing looks like Katalon, Selenium, or Studio, depending on the specific project’s requirements. 

When it comes to test cases, it’s highly recommended that the team covers not only expected scenarios but also edge cases to ensure extensive coverage. In addition, testing conditions should be as close to real life as possible. This will give you confidence that the product is ready to be released to the public. 

Prepare Test Cases

Test cases are an important part of the testing process that helps certify your software product. They act as a checkpoint to ensure that your product meets the set standards and quality. Therefore, it’s important to write them with attention to detail.

To improve your test case development phases, start by identifying the purpose of testing and user requirements. Testers must have a clear understanding of why the product is being developed in the first place and what features it must have to deliver to customer expectations.

It’s important to write test cases on time. The best time is in the early stages of testing, during either the requirement analysis phase or the test design phase. It is at this point that QA engineers can evaluate whether the test cases meet the requirements and make adjustments quickly. 

For test cases to be effective, avoid overcomplicating things. Each case should be easy to understand and execute, with a single, clearly defined expected result. This approach not only makes it easier for testers to evaluate software performance but also leaves no ambiguity.  

Incorporate a Shift-Left Approach

Shift-left testing is one of the recent trends in software development. This approach emphasizes early and continuous testing throughout the development cycle, allowing for early detection of bugs. As a result, if there are any serious issues found, they can be fixed in the initial stages of the software development process, rather than choosing to wait for the last phase, where the cost of fixing bugs multiplies tenfold. 

The strength of the shift-left approach is that it focuses on problem prevention rather than fixing bugs. By encouraging testers to actively participate in testing closer to the beginning of the development pipeline and executing smaller tests more often, it allows teams to quickly gather the initial feedback and take proactive steps to improve their test plans.

Shift-left testing doesn’t always mean executing tests early in development, though. Quite often, it means involving testers in discussions with key business users so they can figure out the requirements from a testing perspective and ensure they know what to look for when coding begins. 

Conduct Formal Technical Reviews

To minimize bugs and defects at later stages of software development, it’s a good practice to regularly conduct formal technical reviews (FTRs). The idea behind FTRs is to test a product when it reaches a mature state while remaining at an early stage to prevent major errors. Participants are typically assigned the roles of reviewers, producers, and speakers. In the end, they all draw a final report that outlines the results of the meeting, including what was reviewed, who took part in the review, and what decisions were made. 

Introduce Code Quality Metrics

You can improve the quality of your software testing by implementing code quality metrics to help your team track success. These metrics can be any indicator that best fits your workflow and allows you to effectively assess code quality. Here’s an example of metrics that can be employed for developing software:

• Reliability. This metric can describe the number of times the code failed and passed during tests.
• Security. Code security can refer to the code resistance against potential vulnerabilities and threats.
• Maintainability. You can measure code maintainability by evaluating the number of lines. In general, the more lines it has, the harder it is to adapt it to new requirements. 
• Testability. This metric can be used to outline testing technologies used to test the product, the documentation attached, and the ease with which new test cases can be added and executed. 
• Performance. Your code’s ability to respond and execute actions in a certain interval of time can help you measure its performance efficiency.
• Usability. Usability can be verified through exploratory testing and measured by satisfaction levels.

 Implement Automation 

According to 35% of surveyed companies, manual testing takes up most of the time within the STLC. To address this challenge and enhance the efficiency of your testing processes, it’s crucial to implement automation. Automated testing allows you to execute tests in parallel, significantly speeding up the time of testing and improving test coverage. It also reduces the chance of human errors, contributing to the accuracy of the results. 

Examples of cases where automation can be particularly beneficial include:

• Regression testing;
• Cross-browser testing;
• Complex, multi-step workflows;
• Load and performance testing. 

Create Comfortable Work Conditions for the Team

It goes without saying that in order for the team to be high-performing, people should have comfortable work conditions and know exactly what they’re expected to do. With this in mind, it’s important to assign roles and responsibilities to the QA team during the planning stage. Typically, there are three roles: QA lead, Manual engineer, and Automation tester. 

Aside from this, you should invest some time in building strong and trustful relationships with your team. Great teams don’t happen just like that. You need to be open in communication and create an environment where your team feels valued and respected. Respect and recognize the individual strengths and contributions of everyone on the team. Also, support and provide opportunities for professional development. By investing in the skills of your team members, you not only amp up their capabilities but also show them your commitment to their growth. 

Last but not least, always stay on top of the trends. Technology is constantly evolving, and staying current with the changes is essential for both your team’s success and the quality of your testing efforts. 

Conclusion

To cut to the chase, testing is an important part of the software development process that ensures the quality of the product. However, if it’s not optimized, it can also be a very time-consuming activity, slowing down your product launches and burning the company’s budget. Therefore, optimizing the STLC can be a strategic move to impact the success of your projects.

Testing may occur at different phases of software development. It can be run during a post-production phase or throughout all stages of the software development phase, depending on the project’s development methodology. Despite this, the need for thorough, well-planned testing remains constant. Follow the steps we’ve covered in this article, and you’ll be able to build better software, have happier customers, and leave your competitors irrelevant.