One of the fundamental aspects of the software development life cycle (SDLC) is software testing. It ensures that software products meet the quality requirements before release. There are various approaches to testing, prominent among them are manual testing and automated testing. These are two core methodologies of software testing and are distinct approaches.
The manual testing approach has a human tester executing test cases, while automated testing uses automation tools to execute test scripts. Since it uses tools, automation testing is usually faster and more reliable for performing repetitive testing tasks, while manual testing is useful in exploratory and usability testing. Understanding the differences between manual and automated testing is crucial to optimizing quality assurance (QA) strategies, reducing time to market, and managing resources efficiently.
This article will discuss the details of manual and automated testing, exploring the definition, methodologies, benefits, and limitations. The article will also explore the key differences between manual and automated testing approaches.
What is Manual Testing?
Manual testing is a software testing approach in which a human tester tests an application without using any tools. In manual testing, testers write the test cases, execute them, and then provide a final testing report about the application software. Manual testing is a time-consuming process and can be prone to human errors.
Key Features
- Manual testing is human-centric and performed by human testers.
- It is conducted to find bugs in the developed software application.
- The tester checks all the application’s essential features while executing test cases without the help of automation tools.
- An experienced tester conducts manual testing to accomplish the testing process.
- In manual testing, the tester acts as an end user to test application features and ensure their correct behavior.
Manual Testing Process
The process of manual testing consists of the following steps:
- Test Planning: Define the scope, strategy, and objectives of testing.
- Test Case Creation: Write detailed test cases based on requirements with clear inputs and expected results or outcomes.
- Test Execution: Manually perform the test steps, examine outcomes, and document results.
- Bug Reporting: Log any discovered defects into a tracking system.
- Regression Testing: Repeat tests as required with each new application version.
When to Perform Manual Testing?
There are certain aspects or situations when manual testing is most helpful. Some of these aspects are:
- User Interface can be tested efficiently with manual testing, which helps find UI rendering bugs.
- Detailed website behavior can be tested using manual testing.
- Humans can use their creativity and intuition to test application behavior.
- Human testers act as end users to perform user acceptance testing, which is more useful than automation tools.
- A human tester can test user experience more effectively than tools.
In general, manual testing should be performed when:
- Flexibility is the Key: QA personnel can quickly test and provide feedback with manual testing.
- For Short-term Projects: When the application being tested is a small one and the testing project is short-term, it is not wise to invest more money and effort. In this situation, manual testing is advisable.
- When Testing End-User Usability: Humans can use their sensibilities, creativity, and intuition to understand the application behavior. In this case, humans can better evaluate the application from the end user’s point of view.
Advantages of Manual Testing
Here are some of the benefits of manual testing:
- Human Insight: Manual testing allows testers to identify issues related to user experience, layout, and visual inconsistencies that tools might miss.
- Fast Feedback: Manual testing provides fast and accurate feedback.
- Ad-hoc and Exploratory Testing: Manual testing is ideal for testing in undefined or unclear requirement scenarios. It is suitable for exploratory, ad hoc, and usability testing, as it allows for human observation and interpretation.
- Versatile: Manual test cases can be applied to many tests, and it is not dependent on the type of application you are testing.
- Flexible: Manual testing is flexible as it adapts easily to changes in the user interface. It allows on-the-spot changes and test improvisation.
- Less Expensive: Manual testing is inexpensive and does not need costly software or frameworks.
Disadvantages of Manual Testing
Manual testing also has several disadvantages. Here are some of them:
- Not All Defects Detected: In manual cases, there is no guarantee that all the defects will be identified and that there will be 100% test coverage. Manual work is also subject to human mistakes, especially in repetitive tasks, and is error-prone.
- High Expertise: Although manual testing can be done by anyone, in some complex situations, high expertise is required. In a competitive market, hiring and retaining high-quality testers can be challenging.
- Lots of Time: Manual testing is time-consuming. It requires a lot of time to develop test cases manually so that all the functionalities are covered and tested. It also requires human effort, which takes more time.
- Lack of Reusability: Manual test cases cannot be reused as the process cannot be recorded. Tests must be re-executed manually after each change.
- Less Reliable: Since humans conduct the testing, there is a chance of human error, and it is not very reliable.
- Not Scalable: Manual test cases are not easily scalable and are difficult to run quickly across multiple browsers/devices.
- Low Test Coverage: When a large number of test cases must be handled, it is difficult to cover all features.
- High Investment: Manual testing requires significant time and resources for effective execution.
What is Automation Testing?
Automation or automated testing is a type of testing that is performed using specialized software tools to execute test cases automatically. It is applied to repetitive, high-volume test cases. Scripts are written to simulate user interactions and verify outcomes.
Automation testing is faster than manual testing as it is performed with automation tools. There is less chance of human errors in the case of automated testing.
Key Features
Automation testing has key features as follows:
- Automation testing relies on scripts and testing frameworks.
- It can execute large volumes of tests faster.
- Automation testing is ideal for regression, load, and performance testing.
- It is generally more accurate due to eliminating human error and using standardized scripts.
- It is significantly faster than manual testing, allowing quicker execution and feedback.
- It enables the execution of repetitive tasks and regression tests.
- Automation needs manual effort to create initial testing scripts.
Automation Testing Process
The following are the steps in the automated testing process:
- Test Planning: Identify candidates (features, areas) that are suitable for automation, as well as tools for automation.
- Test Script Development: Write automation scripts in the chosen language/framework.
- Execution: Test scripts automatically across environments.
- Reporting: Share the logs, screenshots, and pass/fail reports generated by the tool.
- Maintenance: Appropriately update scripts as the application evolves.
When to Perform Automation Testing?
Automated testing is helpful in several situations as follows:
- Repetitive Tasks: Automated testing is the best option when repetitive tasks must be run. For example, in regression testing, when the regression tests must be executed every time there are code changes, automation testing is the best choice.
- Scarcity of Human Resources: When adequate human testers are lacking and tests must be executed within a given time frame, automated testing can be adopted.
Advantages of Automation Testing
Automated testing has the following advantages:
- Detect More Bugs: Automation testing helps identify more bugs and defects in the software. Automated tests are also reliable and objective, reducing human error.
- Reduced Time for Regression Tests: Automated tests are suitable for regression testing, where tests are executed periodically in a repetitive manner.
- Speed and Efficiency: Automated test scripts are executed much faster than manual efforts. They have quick execution times with minimal human involvement.
- Scalability: Testing can be performed across multiple environments and configurations.
- Reusability: Test scripts can be reused and versioned. Tests can be recorded and reused.
- Comprehensive Reporting: Automation tools generate automated logs, screenshots, and data capture that can be used for reporting.
- CI/CD Integration: Easily integrates with DevOps pipelines for continuous testing.
- No fatigue: Test scripts are executed using software automation tools, so there is no fatigue or tiring factor as in manual testing.
- Increased test coverage: Automation tests help to increase the test coverage, as using the tool for testing ensures that not even the smallest unit is left out.
Disadvantages of Automation Testing
Here are some of the disadvantages of automation testing:
- Difficult to Inspect Visual Elements: It is challenging to test visual elements such as color, font size, font type, etc., using automation, as this requires human intervention. Also, it is not suitable for exploratory and usability testing.
- High Initial Cost: Implementing automation has a high initial cost, as the tools required for testing add to the project budget.
- High Test Maintenance: Maintenance of automation tests is high as scripts need updates when the application evolves.
- Skilled Resources: Testers conducting automated tests should be proficient in programming languages, testing knowledge, and automation tools.
- Complex Setup: Automation setup requires infrastructure, test environments, and technical expertise.
Manual Testing vs. Automation Testing
The table below shows key differences between manual and automated testing.
| Parameters | Manual Testing | Automation Testing |
|---|---|---|
| Definition | Manual testing is a process where test cases are executed by a human tester. | In automated testing, the test cases are executed by the automation tools. |
| Speed | Manual testing is slow and time-consuming. | Automation testing is faster than manual testing. |
| Resources requirement | Manual testing requires human resources. | Automation testing needs automation tools and trained employees. |
| Exploratory testing | Exploratory testing is possible in manual testing. | Exploratory testing is difficult in automation testing. |
| Framework requirement | Manual testing doesn’t use frameworks. | Automation testing uses frameworks like Data Driven, Keyword, etc. |
| Reliability | Manual testing is not reliable due to the possibility of manual errors. | Automated testing is more reliable due to automated tools and scripts. |
| Initial Investment | In manual testing, the initial investment is low as it only requires human resources. | The initial investment is high in automated testing for setting up tools/frameworks and skilled testers. |
| Cost | Manual testing is expensive in the long run, as it cannot be reused. | More cost-effective over time. |
| Test Results availability | The test results are recorded manually in manual testing, like in an Excel sheet, so they are not readily available. | In automated testing, automated tools generate logs, screenshots, and reports that are readily available in the automated tool dashboard. |
| Human Intervention | Manual testing allows human observation, intuition, and creativity, which is useful in developing user-friendly systems. | Automated testing is conducted by automated tools and scripts, without any human intervention. |
| Performance testing | Performance testing cannot be conducted with manual testing. | Performance testing, like load testing, stress testing, spike testing, etc. |
| Learning curve | Manual testing is easier for beginners. Programming knowledge is not required. | Programming knowledge is a must in the case of automation testing, as using tools requires trained staff. |
| Documentation | There is no documentation except for test cases and testing reports. | In automation testing, tools generate extensive documentation, and it acts as a training resource for new developers. |
| Best For | Manual testing is best for exploratory testing, usability testing, UI/UX, and ad hoc testing. | Automated testing is suitable for regression testing, load testing, performance testing, and data-driven testing. |
Automation Testing Tools
Various automation testing tools are used for automation testing. Some prominent ones are:
- testRigor: This is a no-code generative AI-based testing platform for end-to-end testing of web, mobile, desktop, mainframes, LLMs, chatbots, graphs, and more. The test scenarios are input to the tool using plain English as scenarios, descriptions, etc. The tool generates a sequence of actions to test a particular feature/scenario in plain English using Gen AI. Read more about testRigor here.
- Selenium: This is an open-source framework for testing web applications.
- TestComplete: This is a commercial tool for UI, functional, and regression tests.
- Cypress: This automation tools used JavaScript and is a fast tool used for modern testing of web apps. Read more about Cypress here.
- JMeter: Java-based tool used for automating performance and load testing.
- Postman: An Automation tool for API testing, such as REST APIs.
When to Use Manual or Automation Testing?
Both the approaches, manual and automated, have their own unique strengths and weaknesses. When deciding on the approach to use, following factors can be considered:
- Testing Schedule: If the project timeline is tight, automated testing can be suitable as it is faster. However, also evaluate the components/features to be tested and whether automation testing or manual testing will give better results.
- Budget Constraints: Evaluate the testing budget and decide which testing approach is more affordable. Prioritize manual testing in case of a limited budget.
- Team Resources: Analyze team skills and size so that if their automation testing skills are better, you can opt for automation testing.
- Specific Project Requirements: Depending on the project requirements, evaluate which testing is better? Analyze testing types so that maximum test coverage is considered. If the project is short term, manual testing is advisable.
It is also crucial to consider testing methodologies while choosing manual or automation testing. For example, using automation testing for load testing a mobile game is more effective than doing it manually.
Below are examples of various testing methodologies along with their optimal testing types:
| Testing Methodology | Optimal Testing Type | Explanation |
|---|---|---|
| Regression testing | Automated | Suitable for frequent and repetitive tasks; Tests can be reused after code changes. |
| Usability testing | Manual | Evaluating user experience needs human interaction and intuition. Testers simulate real-user behavior to assess usability. |
| Exploratory testing | Manual | For exploratory testing, testers need creativity, intuition, and flexibility, which are offered by human testers. |
| UI testing | Hybrid | Depending on the application, a combination of manual and automated testing may be necessary to assess functionality and the user interface. |
| Performance testing | Automated | Performance testing is resource-intensive and requires scaling; automated tools can efficiently simulate load and assess performance metrics. |
| Acceptance testing | Hybrid | Combines both manual and automated approaches; ensures that both functional and non-functional requirements are met before release. |
| Cross-browser Testing | Automation | Tests are automated and executed across browsers. |
Summary
Choosing between manual and automated testing approaches is not binary but contextual. Each approach has its benefits and challenges. While manual testing brings human creativity and intuition, automation testing offers speed, reuse, and integration with modern development practices.
Organizations must evaluate team capabilities, budget, timeline, and project requirements to create an effective test strategy that uses either or both approaches. Therefore, understanding the difference between manual and automated testing is key to successful quality assurance and helps deliver the best user experience and efficient delivery cycles.