Automation Testing Vs. Manual Testing: What’s the Difference?

March 25, 2021

Software testing is a crucial stage in the software development lifecycle. It is a process that is executed to evaluate the performance of a software application. The purpose of testing is to find whether there are any problematic areas that need fixing so that the software functions according to the specified requirements before the product is released to the users. Software testing is broadly categorized into two methods- manual testing and automated testing.

Manual Testing

Manual testing is the most primitive technique in which the test cases are conducted manually by a tester to find defects and bugs without any help from automated tools. Therefore, someone goes on a device to evaluate various components like functionality, performance, and design by clicking through multiple elements of the application. It requires more effort and is conducted before the software can be automated. There are different types of manual testing-

  • Smoke Testing: It helps to determine the core functionality of the software and detect critical defects. It is often used to verify a new functionality that has been introduced to the piece of software.
  • Cross Browser Testing: A website does not look identical on all browsers due to various factors, hence, it is necessary to perform cross-browser testing to ensure a consistent experience across all platforms.
  • Acceptance Testing: It is performed after all bugs are removed to determine how closely the application complies with the user’s needs and expectations. Acceptance testing should be conducted by a client or user so that they can have clarity about how the app will look and act in the real world.
  • Beta Testing: It is the most common test that is done to collect feedback from the users before the software is finally launched in the market. For this type of testing the application must be able to endure a high volume of traffic.
  • Exploratory Testing: It is a form of ad-hoc testing that can be utilized during the entire development as has minimal guidelines which allow the tester to learn and explore the application.
  • Negative Testing: It is done by the QA team or engineers to verify how an application responds to the input of purposely invalid inputs at various stages of development.
  • Usability Testing: This type of testing determines how the user’s behavior and reaction when engaging with your product. It can be conducted during any phase of the development process.

Automated Testing

Automated testing involves the use of robust testing tools and scripts to conduct software tests through repeated pre-defined actions. The same script can be used to compare test outcomes, and report functions. Automated testing is divided into the type of testing, the type of tests, and the phase of testing-

Type of testing:

There are 2 main types, functional and non-functional:

  • Functional: They are written to test the business logic behind an application.
  • Non-functional: They are written to test the non-business requirements, for example, performance, security, data storage, etc of an application.

Type of tests:

  • Smoke Tests: Just like in manual testing, smoke tests cover the most crucial features of a software solution to ensure that it could be further tested.
  • Integration Tests: Integration tests combine all the pieces and functionalities of the software and holistically test them to ensure an efficient operation.
  • Regression Tests: It is conducted through a combination of functional and non-functional tests to determine if the software has “regressed” after a given change.
  • Security Tests: It covers functional and non-functional tests that screen the software for any defects.
  • Performance Tests: Often non-functional tests that help testers evaluate the responsiveness and stability of the software.
  • Acceptance Tests: These are functional tests that determine how acceptable the software is to the end-users before the final release.

Phase of testing

  • Unit: Unit testing is the first phase of testing. It tests the individual components, or units, of software. It is usually done manually before it can be automated.
  • API: Application Programming Interface is tested post the development process to ensure smooth integration between systems and software.
  • UI: The end users interact with the User Interface and it is tested during the execution phase.

Differences between Manual and Automated Testing

Manual TestingAutomated Testing
Tests are conducted manuallyTests are conducted with the help of automated tools
Less reliable due to human errorMore reliable as it eliminates human error
Time-consumingIt is faster than the manual approach
It is difficult to execute test cases in parallel in manual testing as it requires more human resourceAutomation testing can be done in parallel
It is feasible in test cases that are run once or twice and which do not require frequent repetition.It is feasible for test cases that are run repeatedly over a long period of time
Exploratory testing is possibleExploratory testing is not possible
The reports are also generated manuallyA tool generates the test execution report
It is difficult to run manual tests across different operating systemAutomation testing can be easily done on different operating systems
It can fulfill the goal of testing user-friendliness and improve customer experience as it entails human observationSince human observation is not required, it does not guarantee user-friendliness and an improved customer experience.

Advantages and Disadvantages of Manual and Automated testing

As manual testing may have a possibility of human error, similarly any software is only capable of doing things that it has been programmed to do, this is a limitation. Both manual and automation testing are a part of software development, both have their pros and cons.

Pros of Manual Testing:

  • It involves human judgment and intuition which benefits the manual element.
  • Faster visual feedback.
  • Less expensive as it does not require investment in automated tools.
  • When small changes or elements are added to the software, it is easier to test them manually.

Cons of Manual Testing:

  • It is less reliable.
  • It is not possible to reuse the manual test because it is not recorded.
  • Certain tasks or repetitive testing are difficult to perform manually.

Pros of Automated Testing

  • Helps to determine more faults more accurately as compared to a human tester.
  • It is a fast, reliable, and efficient process.
  • You can execute the same kind of testing operations as automated testing is recorded.
  • It supports various applications.
  • In automated testing even the smallest unit is being checked, therefore there is an increased testing coverage.

Cons of Automated Testing

  • Visual aspects of the user interface cannot be tested without human observation.
  • The investment to set up tools for automated testing is higher and increases the cost of testing projects.
  • The testing script also requires debugging.

Considering all of the points above, you must decide which type of testing is more suitable in a particular scenario.

Preference to manual testing over automated testing in the following cases:

  1. In the initial stages of the project
  2. For testing the user interface for visual feedbacks
  3. Writing scripts is time-consuming, therefore, if the project is for short term you can consider manual testing
  4. It should be executed for Exploratory, Usability, and Ad-hoc testing

Preference to automated testing over manual testing in the following cases:

  1. To handle time-consuming and repetitive tasks
  2. When parallel testing is required
  3. When testing is performed across different operating systems
  4. Is applicable in areas of Regression, Load, Performance testing.

Testing is an integral part of the software development journey. Choosing between the two types of testing depends on many factors like the project requirement, time duration, and budget. The optimum results can be derived from manual and automated testing when the right type of testing is utilized in the right environment.