Testing is an integral component of the software development process. It entails a comprehensive assessment of a software to ensure it meets your client’s requirements and goals.

The primary goal of testing is to identify all the defects and errors in the software before the implementation phase. If software defects are not addressed before deployment, they can adversely affect the client’s business. Resolving those issues would involve high costs.

On the contrary, testing allows you to maintain the software quality and gain your client’s trust and confidence. Furthermore, the end product will require lower maintenance costs, as it will perform accurately, consistently and reliably.

With that said, there are many ways to approach software testing. The best approach is the one that executes the testing process rapidly and is in-line with the principles of Agile. In this article, we will explore different software testing stages and explain everything you need to know about the Software Testing Life Cycle (STLC).

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Software Testing Life Cycle Definition

Software Testing Life Cycle (STLC) is a series of well-defined activities that software testers need to complete to ensure the quality of software. Each of the steps in the STLC process needs to be carried out in a systematic way and sequence.

Furthermore, every single one of these steps has different goals and deliverables at the end of its phase. Although different companies may set their own software testing lifecycles, the basic structure of this testing procedure remains the same. In simple terms, it is a method that formalizes how the testing process will be carried out.

software testing levels

Stages of STLC

Testing is one of the most challenging steps of the software development process. It requires close attention to detail and cannot be completed if you don’t apply a methodical approach. This is why software testing is broken down into different stages.

There are a total of four stages of software testing, which include Unit Testing, Integration Testing, System Testing, and Acceptance Testing. With that said, these four stages can be collectively categorized into two types, the first two being verification stages while the last two are a part of the validation stage.

The key difference between both is that the testing conducted in verification stages is based on the processes used during development. In contrast, the validation stage checks the functionality of the finished product and utilizes user feedback in the end.

Furthermore, the former phase of the testing procedure employs White Box testing in its processes. This means that the internal structure of the software is not hidden, and professionals carrying out testing need to know about the implementation of the software.

On the other hand, in black-box testing, the internal structure of the software is hidden, and testers use this technique during the final validation stage. The testers must examine the functionality of the application against the specifications or requirements enlisted by users.

Let us discuss each individual stage in detail to understand the levels of testing in software testing more clearly.

Unit Testing

Unit testing is the first stage of software testing levels. During this stage, testers evaluate individual components of the system to see if these components are functioning properly on their own.

For instance, if your software is based on procedural programming, these units might be individual functions or program processes. On the other hand, in object-oriented structures, these units can be in the form of a single class. Depending on the tester frame, the problem, these units can vary from each other.

Each of the units selected is then tested to check whether or not it’s fully functional. To perform this stage successfully, the tester needs to have knowledge about granular levels of detail. Plus, it’s important to carry these steps out when you are applying any changes to the codebase. By applying unit testing in code changes, you can make sure that all issues are resolved quickly.

Integration Testing

Testers perform integration testing in the next phase of testing. Here, they test individual components of the system and then test them as a collective group. This allows software testers to determine the performance of individual components as a group and identify any problems in the interface between the modules and functions.

Regardless of how efficiently a single component is running, you won’t know if the software is fulfilling its purpose unless you apply integration testing. There are various ways to test individual components as a group, but they can differ, depending on how every single unit is defined.

System Testing

System testing is the final stage of the verification process. In this stage, testers see whether or not the collective group of integrated components is performing optimally. The process is crucial for the quality life cycle, and testers strive to evaluate if the system can fulfill the quality standards and complies with all major requirements.

To maintain impartiality, testers who have not been a part of the development phase of the application, perform the testing of this procedure. Furthermore, the environment for this procedure is extremely similar to the production phase. The system testing stage is significant because it helps the application meet its functional, technical, and business requirements.

System testing is very important because it verifies that the application meets the technical, functional, and business requirements specified by the customer.

Acceptance Testing

Acceptance testing is the final stage of the QA test cycle. It helps evaluate if the application is ready to be released for user consumption. Typically, testers carry out this phase with the help of the representatives of the customer who test the application by using it. Therefore, they will check if the application can perform all the functions specified.

It’s common for software requirements being misinterpreted during development. For this reason, Acceptance Testing is essential to identify any misunderstanding of business requirements and deliver the product that your customers want.

Once you complete this process, you can forward the application to the production phase. If you ignore this step, it’s possible that customers might not get the features they wanted and won’t come back to you in the future.

qa life cycle

Software Testing Life Cycle in Agile

In agile development, every component of the software development lifecycle is optimized for speed and efficiency. This is why testing too needs to be broken down in the software testing lifecycle to ensure every component of application has been verified in terms of quality. Let us break down the software testing lifecycle in agile and look at each step closely:

Requirement Analysis

Requirement analysis refers to the step where the Software Testing Lifecycle begins. Here, the testing team tries to evaluate the requirements of testing and outline which of the given requirements they can test.

In case they fail to understand the testing requirements, they can refer to stakeholders, such as the customer, system architect, or business analyst. If these testers understand the requirements of the application comprehensively, it is easier to identify faults in the software.

The specifications of any given system can be either functional or non-functional. This means that the testers must check functional business features as well as metrics, such as speed, reliability, availability, and security.

For this reason, testers need to outline the types of tests needed for testing, gather information about the priorities in testing, and configure a traceability matrix for requirements (RTM). Furthermore, they need to present information regarding where the test would be carried out as well as Automation Feasibility Analysis if required.

Software Testing Planning

Software testing requires the effort of an entire team, and senior testers or the manager of the testing team needs to plan the testing process.  This stage of the QA lifecycle results in documents, such as Effort Estimation and Test Plan. The main goal of this procedure is to outline effort and cost estimates for your project.

Managers can prepare the test plan for different types of software testing, select which testing tool is optimal, and evaluate effort estimation. At the same time, they need to assign responsibilities and roles to their team.

Test Case Development

The Test Case Development phase results in the creation of test cases and their corresponding scripts. The test team needs to create, verify, and remake specific test cases, based on specific features and their requirements. Furthermore, they also need to come up with testing data that they can use for their test cases and scripts.

Environment Setup

The test environment comprises testing conditions, such as hardware and software specifications used during the testing procedure. Ideally, it should imitate the environment used by the end-user in his/her working space. The testing team is required to set the testing environment completely and check the readiness of the testing environment (smoke testing).

This means that the testing team must have knowledge of the architecture, software, and hardware specifications of the environment.

Software Test Execution

In the Test Execution phase, testers carry out testing according to the test plans and test cases created by the team. They will evaluate if all the requirements in the RTM match out and report any errors they find in the testing procedure. They will then report the testing errors to the developers working on the project.

Furthermore, the team needs to document all test results and log any case that has failed. Afterward, they need to map the bugs with the test cases in the RM and keep track of these bugs until closure.

STLC Closure

In the end, the entire testing team will meet, exchange information, and analyze testing documents to optimize the testing strategies. The goal of this phase is to give feedback about any bottlenecks faced during the software process and establish best practices for projects of similar requirements.

Shift-Left Testing Process

Shift-left testing is an approach of software testing suited for agile development. In this approach, critical testing procedures are “shifted left”, which means they are shifted to early phases of the development cycle. Shift-left testing is the go-to testing procedure in Agile, DevOps, and Continuous Development environments.

The main concern in late testing is that it takes longer to pinpoint what had gone wrong during development, which means that the costs inadvertently go up. Shifting critical testing procedures to early stages helps to expose and stop problems earlier.

The method allows testers to identify, localize, fix, and perform regressions tests to clean out all bugs in the application. If you don’t reduce these problems through early testing, they may pile up and become even harder to detect as the software production and integration continues.

On the other hand, using mature testing techniques helps identify critical issues in the application under minimal lower costs. For instance, they can create a comprehensive set of unit test cases that cover most of the codebase.

At the same time, functional and API testers can minimize relying on late testing by testing early and often. As a result, they don‘t have to depend on late testing to identify bugs, and they can use it to see whether the functional requirements check out.

Furthermore, if you include testing practices, such as test automation, you can root out problems in the software even earlier and identify issues more cost-effectively.

levels of testing in software testing

Testing Life Cycle in PFLB

The delay caused by late testing has a direct effect on the total cost of a project. Furthermore, it can also have an adverse effect on the quality of the product. To prevent such problems from happening, you need to perform all stages of software testing in detail.

PFLB is one of the leading software testing service providers out there. Since its inception, the company has been providing software-testing services to over 500 companies across all industries, from finance and healthcare to retail and technology.

Besides that, the company focuses on continuous testing, streamlining continuous integration, and ensuring continuous delivery of tested components. Lastly, with the help of test automation, the company can significantly accelerate the launch of your product and reduce the cost of test iterations.

To summarize, software testing is an integral component of the software development process. Without the correct implementation of software testing practices, you can incur high costs for your project.

An experienced software testing company will carry out all the steps of the software testing lifecycle for you and identify all possible bugs in your application. Furthermore, by trusting a reliable software testing service provider, you can ensure that you meet the customer’s requirements and complete the project in the given budget and time. It’s difficult to find a software testing service that has enough experience to bring value to your project and take care of the entire testing process on its own. PFLB specializes in providing quality assurance services in software applications across all major industries. They have years of testing experience, backed by expertise in working with dozens of products. For comprehensive software testing services, contact PFLB now.

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