Manual Testing Explained—What Is It and Why Is It Important?

Software testing is a term that encompasses many different types of testing used to evaluate and verify the quality of a software product. In fact, there are many different types of software testing, like manual testing, automated testing, security testing, accessibility testing, and audio and video testing—just to name a few. 

However, when it comes to planning an effective QA strategy, the usual dilemma companies face is whether they should perform manual testing or replace it with test automation. 

And while many companies do decide to automate a good portion of their testing processes as a way to be more efficient, manual testing still plays a critical role in a successful QA strategy. According to an expert panel of technology leaders, manual testing remains important and impactful when testing software.

In this blog post we will focus on manual testing—explain what manual testing is, discuss why it’s important, explore the different types, and provide a step-by-step guide on how to perform manual testing effectively. Let’s get started.

What is manual testing?

Manual testing is a type of software testing in which a tester runs test cases manually without using automated tools. The purpose of manual testing is to uncover bugs, defects, and issues in software applications, products, and systems. It's the most basic testing method and is essential for detecting major issues in the software related to various aspects of quality, including functionality, usability, and performance.

Manual testing ensures that the application functions correctly according to specified requirements, verifies the quality of the system, and ultimately delivers a bug-free product to the user.

Why is manual testing important?

There are numerous reasons why manual testing is important and cannot be completely replaced by automated tests. Namely, while manual testing can be time-consuming, it offers certain advantages, such as the ability to adapt to changing requirements and providing human insight and intuition that automation may lack. Here are some instances that highlight the importance of manual testing:

1. Manual testing relies on human perspective. Automated tests lack human senses, which can be crucial for assessing visual aspects of an application's interface. Manual testing is essential, especially for complex user interfaces with animations or interactive elements.
2. Manual testing can be more efficient than automation. There are some instances when manual testing can be the more efficient testing approach—when a software product is still in early development, is undergoing changes, lacks stability, or is too complex.  
3. Manual testing supports exploratory testing. Manual testing is indispensable for exploratory testing, where testers evaluate the system on-the-fly without predefined test cases, enabling quick identification of major flaws.

Step-by-step guide on how to perform manual testing

Step 1: Understand client requirements 

The first step is to understand the client’s requirements for the project. Specifically, what needs to be tested and what the expected outcomes are. Start by getting familiar with the software's functional and non-functional requirements, as well as any design documents or user stories. Then create a dedicated team of manual QA engineers whose skills and qualifications match the client's needs.

Step 2: Prepare a test plan 

After the QA team is set up and familiar with the project requirements, the next step is to write a good test plan, that includes the following:

• The scope of the project 
• Testing objectives 
• Resources required for testing
• Testing techniques, tools, and environments that are most suitable for the particular case

Step 3: Design the test cases

Develop detailed test cases based on the requirements, covering various scenarios and functionalities of the application—as identified in the previous steps. Each test case should include preconditions, steps to execute, expected results, and postconditions.

Step 4: Set up test environment 

Before any tests are executed, the QA team needs to prepare the testing environment. This includes installing the software application, configuring necessary settings, and ensuring access to relevant data and resources.

Step 5: Execute tests

When the setup is finalized, the QA engineer can start executing manual testing cases one by one, following the steps outlined in each case—interacting with the application as an end user would, inputting data, navigating through screens, and performing operations according to the test case instructions.

Step 6: Report defects 

While executing the test, it's crucial to document and report any defects or bugs, including detailed information such as steps to reproduce, actual results, expected results, and severity level.

Step 7: Track defects 

After the test is complete, the QA tester must log the reported findings into a tracking system, such as a bug tracking tool, assigning priorities and statuses.

Step 8: Perform regression testing 

After all bugs are caught and fixed, the tester should perform regression testing following best practices to ensure that the changes have not introduced new issues and that existing functionality remains intact. 

Step 9: Prepare test closure reports 

After regression testing, the QA team must evaluate the test results against the defined criteria to determine whether the testing objectives have been met and prepare a test summary report documenting the testing activities, results, and any outstanding issues.

Step 10: Gather feedback and suggest improvements 

As the last step in the manual testing process, the QA team should provide feedback to stakeholders on the quality of the software and suggest improvements in future iterations.

Manual testing vs. automated testing

It's worth highlighting that neither manual nor automated testing holds a clear advantage over the other, particularly when assessing elements such as project size, complexity, testing cadence, resource availability, and testing aims.

While some clients opt for one testing approach or the other, in practice, a blend of both usually produces the best outcome. This is particularly true when, within one particular project, manual testing is chosen for exploratory and usability testing, while automation testing is used for repetitive and resource-intensive tasks.

Below we have summarized the fundamental differences between both approaches to help determine the most suitable one for your specific requirements.

Different approaches to manual testing

Black box testing, white box testing, and grey box testing are three fundamental approaches to manual software testing. It’s important to note that any of these testing methods can be executed both manually as well as using an automation tool.

Black box testing

Black box testing is a software testing method that involves testing the functionality of a software system without having access to its internal code or structure. Testers focus solely on the system's inputs and outputs, treating it as a "black box" where they cannot see its internal workings. 

The goal is to verify that the software functions correctly according to its specifications and meets user requirements. Testers simulate various user scenarios and interactions to identify defects or inconsistencies. Black box testing is ideal for assessing the software from an end-user perspective, ensuring it behaves as expected without needing knowledge of its internal implementation.

White box testing

White box testing is a software testing method that, in contrast to black box testing, examines the internal structure, design, and code of the software being tested. Testers have full access to the system's source code and use this knowledge to design test cases that assess the system's internal logic, algorithms, and data structures. The focus is on validating the correctness of the code and ensuring its robustness, efficiency, and maintainability. 

White box testing is often performed by developers or testers with programming expertise who can analyze the codebase and identify potential weaknesses or vulnerabilities. It complements black box testing by providing insights into the system's internal behavior and uncovering issues that may not be apparent from external testing alone.

Grey box testing

Grey box testing combines elements of both black box and white box testing. This technique is used to test the system from a developer’s perspective, where the focus is on testing some of the system’s internal workings but not all. QA engineers leverage this partial knowledge to design test cases that cover both functional and structural aspects of the system. 

Grey box testing is useful for scenarios where some knowledge of the internal implementation is necessary to create effective test cases, but full access to the codebase is not available or practical. It strikes a balance between the thoroughness of white box testing and the external perspective of black box testing, offering a pragmatic approach to testing complex software systems.

What are the different stages of manual testing?

Manual testing can be divided into 4 stages:

1. Unit Testing 

Unit testing is the earliest stage of testing in which individual components or units of software are tested in isolation. These units can be functions, methods, or classes. The primary focus is on verifying the correctness of each unit's functionality and behavior according to its specifications or requirements. Test cases are designed to cover specific functionalities of each unit, ensuring that they work as expected and handle different input scenarios appropriately. Testers or developers typically write unit tests using testing frameworks or tools. They execute these tests to identify defects or errors within the individual units before integrating them into the larger system.

2. Integration testing

Integration testing follows unit testing and focuses on testing the interactions between individual units or components when they are integrated to form larger modules or subsystems. The main goal is to verify that the integrated units work together seamlessly and communicate correctly, adhering to the specified interfaces and protocols. Test cases are designed to validate the flow of data, control, and functionality between integrated units, ensuring that they cooperate as intended without issues. Testers execute integration tests to detect integration faults, such as interface mismatches, data corruption, or communication errors, and ensure the overall system's stability and reliability.

You might be interested in: Unit Testing vs. Integration Testing

3. System testing 

System testing assesses the entire software system as a whole, including all integrated modules and components, to validate its overall functionality and behavior. The primary focus is on testing the system's compliance with requirements, specifications, and business objectives, as well as performance, security, and usability aspects. Test cases cover end-to-end scenarios and use cases, simulating real-world usage environments and user interactions to uncover defects or discrepancies. Testers execute system tests in environments that closely resemble the production environment to identify system-level issues, assess its readiness for deployment, and ensure it meets stakeholders' expectations.

4. Acceptance testing

Acceptance testing, also known as User Acceptance Testing (UAT), is the final stage of testing conducted to determine whether the software meets the acceptance criteria and is ready for deployment. The primary focus is on validating the software from the end user's perspective, ensuring it meets business requirements, user needs, and expectations. Test cases are designed based on real-world scenarios and user workflows, covering typical usage scenarios and critical functionalities to validate the software's suitability for production use. Testers, often including end users or stakeholders, execute acceptance tests in a simulated or production-like environment. They verify that the software behaves as expected, meets predefined acceptance criteria, and fulfills business objectives. Any discrepancies or issues identified during acceptance testing are addressed before final deployment.

The bottom line

We can come to the conclusion that while automated testing continues to evolve and gain prominence in the software testing landscape, the importance of manual testing cannot be overstated. Manual testing remains indispensable for its human-centric approach, allowing testers to uncover nuanced issues, assess user experience, and ensure overall quality with a depth that automated tools may struggle to achieve. 

From early unit tests to comprehensive acceptance testing, the human touch in manual testing offers invaluable insights, flexibility, and adaptability that complement automated processes. By integrating both manual and automated testing methodologies effectively, companies can enhance their testing efforts, mitigate risks, and deliver robust, high-quality products that meet user expectations and business objectives. 

In need of manual testing services?

Are you looking for manual testing services to ensure your software product meets all the requirements in terms of quality? We perform manual testing on more than 3,500 real devices and cover a variety of platforms, operating systems, versions, manufacturers and configurations. Our team of ISTQB certified QA engineers have extensive experience in using industry-leading software testing tools and frameworks that will provide you with a detailed test report that will include all the metrics you need. We can either use available tools to create our own test report or use a tool or report template provided by you.

Schedule a call with us today and let’s collaborate to ensure that your product checks all the quality boxes.