Functional Testing vs. Traditional Manual Testing: Pros and Cons

Functional Testing vs. Traditional Manual Testing: Pros and Cons

Software testing ensures programs run properly and are error-free, protecting the user experience, security, and functionality. A software or system component must be executed to assess one or more properties of interest. To put it simply, the goal of automation testing is to find inconsistencies between the requirements as written and the actual requirements.

Functional and manual testing are essential in software development, each with pros and cons.  Teams aware of these can use the appropriate testing techniques to increase the caliber of their products and the productivity of their development process.

What is Functional Testing?

Software testing that confirms that every program function runs per the necessary specification is known as functional testing. Functional testing’s primary goals are to test the software system’s functionality, client/server apps, databases, APIs, security, and user interface. The objective is to ensure the application performs its intended functions correctly and as expected.

The main goals consist of:

  • Software validation concerning functional requirements and specifications: Ensure the program operates as intended in all circumstances, even the most unusual ones.
  • Functional error detection: Finding scenarios where the program cannot accomplish its intended tasks.
  • Assurance of user satisfaction: Verifying that the program can carry out necessary operations in practical situations.

How is it Performed?

Functional testing can be done automatically with tools or by hand. Project needs, budget, and schedule determine strategy.

  • Manual Testing: Testers test cases by hand without scripts or tools. This method works well when test cases are run infrequently, as in exploratory testing.
  • Automated Testing: This method utilizes automation testing tools and scripts to execute predefined test cases automatically. It is very effective for regression testing, which involves frequently repeating tests across different software versions. Functional tests can be automated with tools like QTP (QuickTest Professional) and Selenium.

Key Characteristics

Here are some of the key characteristics of functional testing –

  • Specification-based: Functional testing uses software component specifications. Testers need not understand application internals.
  • User Scenario Simulation: This method simulates user scenarios to ensure real-life program functionality.
  • Black Box Testing Method: Functional testing is black-box testing in which the tester is unaware of the program’s architecture.
  • Comprehensive Coverage: It checks every software feature to meet specifications.
  • Automatability: Functional testing is highly automatable, allowing frequent and extensive testing.

Verifying that a software application is ready for release requires functional testing. Before the software goes live, it ensures that any possible problems are found and fixed and that the product satisfies the user’s needs.

Read Also: Mobile App Testing Best Practices: A Functional Approach

What is Traditional Manual Testing?

Manual testing, where testers run test cases by hand without automated tools, is essential to software testing. This method involves human interaction with the application to identify unexpected behavior or bugs. By assuming the role of an end user and following a realistic process, the tester ensures that all application features work as intended.

The key objectives include:

  • Finding bugs automated tests miss: Manual testing allows testers to find issues not considered during test planning through exploratory testing.
  • Making sure the app meets user expectations: By using the app, testers can better assess its design, usability, and satisfaction.
  • Checking features and functions:  Testers ensure each feature works as intended from the user’s perspective.

How is it Performed?

The steps involved in traditional manual testing closely resemble those an end-user would take when interacting with the application:

  • Test Planning: Examiners draft a plan that specifies the objectives, materials, schedule, testing methodology, and deliverables.
  • Creating Test Cases: Using the requirements, testers write detailed test cases that include test parameters, desired outcomes, and actual results.
  • Testing Environment Configuration: Testers configure hardware and software as needed.
  • Testing: Testers manually carry out the test cases, paying close attention to how the application behaves and noting any deviations from the desired outcomes.
  • Recording Defects: Any problems or defects found during testing are recorded and sent to the development team for fixing.
  • Testing again and Regression Testing: Following defect correction, testers test the affected functionality again and run regression tests to make sure the modifications have not had an unfavorable impact on other areas of the application.

Key Characteristics

Let us look at some of the key characteristics –

  • Human-centric: Manual testing depends on the tester’s aptitude, judgment, and experience to investigate the functionality of the program and spot problems.
  • Flexibility: As tests are conducted, testers can swiftly modify their strategy in response to new information.
  • Cost-effectiveness for small projects: Setting up automated testing frameworks can be more expensive for larger projects than conducting manual testing.
  • Comprehensive User Experience Testing: Manual testing helps evaluate an app’s visuals, usability, accessibility, and user interface.

Pros and Cons of Functional Testing

Automated testing, in particular, is the foundation of contemporary software development processes.  It verifies that applications fulfill the necessary conditions. However, just like any testing strategy, it has advantages and disadvantages.


  • Automation increases efficiency and speed

Automated functional testing significantly reduces test completion time, especially for large and complex applications. After writing test scripts, the development team can run tests frequently and get feedback.

  • Consistency and coverage

Automation allows thorough testing of input types, user scenarios, and system states. Automated tests can be run regularly to test every application part, reducing human error.

  • Ideal for regression testing and large codebases

Functional testing aids regression testing, which finds bugs in previously tested software after changes. Running automated functional tests when needed simplifies quality management in large, frequently updated codebases.


  • Initial setup cost and complexity

Setting up an automated functional testing environment can be expensive and difficult. Especially for large and complex applications, developing and maintaining test scripts takes time, resources, and an investment in testing tools.

  • Requires technical skills for script writing

Writing effective test scripts requires technical skills and a deep understanding of the application under test. Testers must know programming languages and automation frameworks, which may limit non-technical team members’ testing participation.

  • May fail to identify visual or user experience problems

Conducting functional testing is a great way to ensure that an application functions as intended. Still, it may miss usability, accessibility, and design issues. These aspects are often better assessed through manual testing methods.

Pros and Cons of Traditional Manual Testing

Software testing still includes a significant amount of manual testing, particularly when automated testing is ineffective. However, it provides certain difficulties that could compromise the reliability and efficacy of testing.


  • No technical scripting knowledge required

Manual testing does not require programming or scripting, so testers of all backgrounds can use it.  Testing from a broader perspective may reveal issues that a technical tester might miss due to its inclusivity.

  • Better at identifying visual and user experience problems

Manual testing is especially good at spotting visual problems and problems with the user experience that automated testing may overlook. Testers can evaluate the application’s overall user interface, usability, appearance, and feel to ensure it is functional and easy to use.

  • Flexibility in investigating and modifying tests

Because manual testing is dynamic, testers can modify their strategy in response to findings as they occur. This adaptability is especially important for exploratory testing, where the goal is to find bugs or unexpected behaviors not anticipated during the test planning stage.


  • Taking longer and being less effective

Manual testing takes much longer than automated testing for large-scale applications or those needing frequent regression testing. For projects with short deadlines, manual test case execution can slow down the development cycle and reduce efficiency.

  • Prone to human error

Using human testers raises the possibility of mistakes during the testing procedure. Software quality may be jeopardized if tests are executed inconsistently or with fatigue, inattention, or a misinterpretation of the requirements.

  • Exact test conditions are difficult to replicate

Manual testing may need help reproducing the test conditions exactly for every execution, which can cause test results to vary. Because of this inconsistency, it may be difficult to confirm whether a bug has been successfully fixed or whether a behavior change in the application results from a novel problem or a test environment variation.

Comparing Functional and Traditional Manual Testing

It is important to consider the unique qualities, benefits, and constraints of functional and traditional manual testing within the context of the software development lifecycle.  This comparative study emphasizes their application scenarios, financial ramifications, skill needs, and general influence on the development process.

Application Scenarios

Functional Testing is best suited for:

  • Validating specific requirements or functionalities of the software against predefined expectations.
  • Automated regression testing to ensure new changes have kept existing functionalities intact.
  • Large-scale testing scenarios where automating tests can significantly reduce execution time.

Traditional Manual Testing excels in:

  • Early development stages, where the software is still evolving, and automated tests would require frequent updates.
  • Usability and exploratory testing to assess the user interface, user experience, and overall satisfaction.
  • Cases where human intuition is crucial for identifying subtle issues that automated tests might overlook.

Cost Implications

Functional Testing:

  • Higher initial costs due to the need for automation tools and the development of test scripts.
  • It can reduce manual test execution and enable more frequent and consistent testing cycles, saving money over time.

Traditional Manual Testing:

  • Lower initial costs since it doesn’t require sophisticated tools or extensive setup.
  • In the long run, it may become more costly due to the intensive labor required and the potential need for repeated test cycles.

Skill Requirements

Functional Testing:

  • Requires technical skills to write and maintain test scripts, including programming and understanding automation frameworks.
  • Testers must be proficient in automation tools and test results interpretation.

Traditional Manual Testing:

  • Programming skills are not needed, making it accessible to more testers.
  • Improves analytical skills, detail, and user behavior and expectations.

Impact on Software Development Lifecycle

Functional Testing:

  • It can significantly accelerate the testing phase, especially with automated tests, allowing for quicker feedback loops and iterations.
  • Enhances the reliability of the testing process by ensuring consistent test execution and coverage.

Traditional Manual Testing:

  • Provides valuable insights into the user experience and interface design, which are critical for user satisfaction but may slow down the testing phase due to its time-consuming nature.
  • Allows testers to adapt and explore based on test results.

Today’s web app users access them from multiple devices, browsers, and operating systems, so a seamless user experience is essential. Automation, especially cross-browser testing, is essential.

Without manually testing every possible combination, developers and the QA team can swiftly assess web application functionality, performance, and visual consistency across environments. This ensures that end users, irrespective of their browser or device, have a flawless experience by expediting testing and enhancing test accuracy and coverage.

LambdaTest is an AI-powered test orchestration and execution platform that transforms teams’ approach to cross-browser and automation testing. It provides a wide range of testing tools designed to meet the requirements of modern web development.

With access to more than 3000 real browser and OS combinations, LambdaTest guarantees that your web applications function flawlessly for every user, regardless of how specialized their browser or preferred device may be.

With LambdaTest, you can integrate automated testing workflows into your CI/CD pipeline for continuous testing and deployment. This integration automatically tests web application changes, speeding up development and reducing time to market.

LambdaTest allows parallel testing across browsers and OSes. This drastically reduces the time required for comprehensive cross-browser testing, enabling you to deliver high-quality web applications faster than ever.


We have examined Functional Testing vs. Traditional Manual Testing’s definitions, goals, methodologies, and software development lifecycle benefits and drawbacks.  Functional testing, especially automated, is efficient, consistent, and can handle large volumes of tests across complex systems.  In contrast, traditional manual testing provides the human insight to evaluate user experience, usability, and software behavior in real-world scenarios.

Finally, Functional Testing and Traditional Manual Testing can create high-quality software that meets technical requirements and provides a compelling user experience. Development teams can ensure their products are functional and enjoyable by carefully considering each project’s needs and using a strategic mix of testing methods.