Types of Testing in Software Engineering

Software testing is a complex process, where personalized methods and approaches are often developed. It’s common for industry newcomers to confuse methods (black box, white box, etc.), approaches (automation or running manual tests) of testing with the actual software testing types.

Software testing activities can be categorized the following way:

• Functional activities that ensure if a product meets technical requirements, all the features work as intended;
• Non-functional activities that validate performance, ease of use, security, and user satisfaction with the project.

These categories have multiple software testing types — here’s the rundown on them:

Unit Testing

Unit testing is a defining component of the early development process. It’s common to complete unit tests without the assistance of QA experts. Unit testing logs are deployed as a reference point for testers. During unit testing, the code is broken down into basic blocks — units that are tested autonomously. 

What System Components Are Under Test?

The scope of unit tests is to assess the operation of the basic building block — a structure with a few outputs and one input. The following structures can be considered units:

• Method;
• Function;
• Procedure.

The Goal of Unit Testing

This type of test helps business owners be confident that the blocks of a system behave as determined by the service-level agreement and comply with industry standards. Unit test reports are used as a reference point by the QA team and are often referred to on later stages of functional testing.

Advantages of Unit Testing

• Helps keep the project up and running. By checking whether individual code blocks operate with no errors after modifications helps reduce the potential harm of adding new features and makes it easier to pinpoint defects.
• Facilitates employee onboarding. Looking at the documented outcomes of unit tests offers a developer a solid understanding of the block’s function and the way it operates.
• Is autonomous. Units are approached as independent modules — every block is tested autonomously. Thus, there’s no need to wait for all system components to be designed to run unit tests.

Integration Testing

Integration testing is the way of validating the connection between individual modules as a joint subsystem. The activity usually follows unit testing and is crucial to be confident in the absence of errors in interactions between client-side and server-side subsystems, as well as the product with a distributed architecture. A key approach that aligns with ensuring system reliability is understanding site reliability engineering (SRE), which focuses on automating processes to maintain scalable, reliable systems while managing overall system health.

What System Components Are Under Test?

There are two types of software tests with the scope of assessing integrations:

• Running integration testing on software modules — the approach exposes interface and interaction defects on the scale of basic product unit;
• System integration testing — validates the joint functionality of compound software complexes.

The Goal of Integration Testing

The aim of integration testing is to pinpoint interaction flaws between system blocks. As a result of completing the activity, quality assurance teams will verify if the solutions meet the service-level agreement. 

Advantages of Integration Testing

• Broad scope — running tests offers QA teams to cover most parts of the system since one test uses at least two endpoints;
• Starts on the beginning stages of development and is useful to track system defects before moving further down the software development life cycle;
• High accuracy of flagging system-level flaws — there’s no room for two-way interpretation of interface interactions.

System Testing

System testing has a wider scope than that of unit or integration tests. It ensures that the project meets functional requirements. System testing is impossible to complete without the assistance of a QA team, well-versed in the domain (domain knowledge allows testers to mimic the behavior of the end-user more precisely). 

What System Components Are Under Test?

System testing is needed to check the functionality of the project under conditions, similar to a post-release production environment. 

The Goal of System Testing

System testing validates end-to-end scenarios, observing the amount of time users spend on the website or the application in detail. The process is conducted from a user’s standpoint, without analyzing the source code.

Advantages of System Testing

• Provides a big picture view of how the product operates — that of the end-user;
• Helps make sure that putting several subsystems together won’t lead to shutdowns and system failures;
• Promotes stakeholder assurance in the project’s ability to deliver business goals.

Regression Testing

When there’s a change in the system, it’s not enough to only test the functionality of the modified chunk of code since it’s likely that the modification impacted the code elsewhere even if the code in question is working flawlessly.

To make sure no bugs are left in the system after a change or an update, quality assurance teams conduct regression tests — one of the QA testing types. 

What System Components Are Under Test?

The entire system is involved in the process — essentially, the whole activity is a re-run of previous test cases. 

The Goal of Regression Testing

Regression testing helps developers be confident in the error-free performance of an app’s critical features: whether they are jeopardized by software updates, functional adjustments, and other routine maintenance tasks. Testers need to test for regression as soon as the system has been modified. 

Regression Testing Advantages

• High test coverage — the activity allows re-testing the entire product;
• Higher customer satisfaction — regression testing helps release bug-free system updates and be confident that end-users will not be irritated by defects and errors;
• It doesn’t require much planning and preparation since regression testing relies heavily on the existing test suite.

Acceptance testing

Acceptance testing is conducted as the last testing activity among software development testing types. Quality assurance specialists stage it to predict how the product operates after the release. Acceptance testing is crucial since it serves as proof of a QA team’s efficiency for stakeholders and business owners. 

What Components Are Tested?

The entire project is tested to guarantee the absence of contractual mismatches between the vision of the tech team and project stakeholders. 

The Goal of Acceptance Testing

This is a type of testing in software engineering geared towards dealing with issues that can have any negative impact on conversion or speed of lead generation. It usually helps flag and fix cosmetic issues — spelling errors, vague navigation, duplicate pages. The desired outcome for the team is to satisfy project stakeholders with the project’s functionality. 

Advantages of Acceptance Testing

• Makes sure there’s no misalignment between management and the tech team;
• Flags defects that might lead to financial (fixing any bug after release is more expensive than mitigating the issue before the project is brought to the market) and reputational losses if left unattended;
• Has a wide test coverage and gives business owners full confidence in how the product functions.

These were the stages of functional software testing. The second important set of activities QA teams need to perform are non-functional tests. Take a look at the must-have non-functional types of QA testing.

Performance Testing

Performance testing service is a way to examine the performance of the tool when it is used by a forecasted number of people. 

What System Components Are Under Test?

Performance testing handles improving page loading time and reliability of the app under higher user loads, as well as its compatibility with different devices. There are different types of software testing: QA specialists can test the system’s capability to withstand high user loads, the way it performs across different time zones, the way users interact with databases, etc. For thorough testing of system scalability and reliability, using an API performance testing tool can help ensure the system can handle stress under various conditions. 

The Goal of Performance Testing

Performance testing doesn’t focus on flagging the functional problems of the software. Unlike functional software test types, it assesses the project’s ability to scale, as well as its performance on low-end devices. Running performance testing helps eliminate post-release frustration and improve traffic retention. 

Advantages of Performance Testing

• Improves the potential the application has to scale;
• Helps ensure users are not frustrated with the final build;
• Ensures that the product corresponds to the vision of a business owner.

Usability Testing

Monitoring usability is one of the black box types of testing in software testing that requires recording live interactions with the website and pinpointing defects that keep business managers from creating an intuitive user experience.

What Components Are Under Test?

Usability testing assesses the entire system based on these criteria:

• Safety;
• Ease of navigation;
• Memorability;
• General user satisfaction.

Goals of Usability Testing

Usability testing helps predict user’s feedback after trying out the final product and find ways to improve it. 

Advantages of Usability Testing

• Stakeholders are confident that prospects can complete buyers’ journeys effortlessly;
• Increases the level of user satisfaction with the product;
• Facilitates routine post-release tasks.

Security Testing

QA teams run different types of testing in QA to validate the way data resources of the software are protected from accidental exposure and third-party attack. On top of that, a company manager can ensure the product’s legal compliance. 

What Components Are Under Test?

Security testing assesses the server-side of the project according to a set of criteria:

• Integrity;
• Data storage confidentiality;
• Authentication;
• Input validation;
• Session management flaws;
• Protection from XSS and other attacks.

The Goal of Security Testing

Security testing gives business owners confidence that the product is fully equipped with alert mechanisms and can pinpoint threats with no human supervision. It assesses protection mechanisms and ensures the program’s compliance with legal regulations.

Other than that, security testing is conducted to measure the potential impact of a threat and come up with preventive mechanisms to mitigate threats. 

Advantages of Security Testing

• Brings long-term financial savings as it allows to forecast and deal with security threats before the solution is out;
• Wide range of assistive tools that increase the efficiency of the QA workflow;
• Uncovers issues that were not identified by previous types of testing in software.

Portability Testing

Portability testing is crucial for time-efficient application maintenance. It assesses the ability of a system to be moved to a different server or adopted as a part of a new system. In testing theory, this testing type is often seen as a part of system testing. 

What Components Are Under Test?

Portability testing either focuses on ensuring that the system is easy to migrate between multiple hardware modifications and can be run on every popular browser operating system. 

The Goal of Portability Testing

Portability determines if the interface and the functionality of the application don’t change among different platforms. It offers teams a possibility to move the server from one server to another and makes it easier to keep the app up and running. 

Advantages of Portability Testing

• Helps ensure the software has flawless performance on most common browsers and devices;
• Facilitates the application’s scalability;
• Ensures a comfortable user experience, independent of the platform the audience uses to run the project.

Software Testing Service with PFLB

Software testing is a complex procedure that encompasses various subtypes. Although some testing stages are fairly easy to manage, while others are highly multi-layered. To run a full range of software testing tasks, reach out to PFLB. Our company has certified QA specialists, with years of experience in debugging small-scale and large-scale projects in e-commerce, finance, healthcare, education, and other domains. Here’s how we help businesses:

• Conduct testing both manually and with the assistance of automation platforms. Depending on different kinds of testing, budget, and deadline constraints, our team will either oversee tests or automate them to speed up the development process;
• Continuous testing. Every PFLB tester is well-versed in DevOps practices — we can validate the system while it’s still in development to improve workflow agility and development efficiency;
• Consulting — if you have an in-house team but struggle to build a sustainable testing workflow, reach out to our team for consults.

Take a look at our case studies to see how our testers approach quality assurance. We are looking forward to discussing your software product — feel free to leave us a message.