Automated vs. manual Testing: Differences

Manual testing vs. automated testing. Which one is better and more suitable? How to compare the two software testing techniques? In our thorough article, you will get to know all the details of manual and automation testing, including the comparison of both approaches and their pros and cons.

What's the difference between automated vs manual testing?

Manual and automation testing modes differ in regard to a lot of various aspects of software testing. What are the main differences when we compare manual testing vs automated testing? We have listed them in a handy table below:

Aspect of testing	Manual testing	Automated testing
Investment	For manual testing, investment is required for human resources only.	Here, investment is required for testing tools as well as automation engineers.
Setup	Manual testing needs a straightforward test execution setup	Automated testing requires far less complex test execution setup.
Programming skills	There is no need for programming in manual testing.	Programming knowledge is a must to conduct automation testing.
Test design	Manual unit tests do not drive design into the coding process.	Automated unit tests enforce test-driven development design.
Framework(s)	Manual testing does not use frameworks. However, it might make use of guidelines, checklists and some strict processes for drafting certain test cases.	Automated testing uses many various frameworks such as Data Drive, Keyword, Hybrid to accelerate the automation process.
Test coverage	Manual testing hardly ever ensures sufficient test coverage.	Automated testing easily ensures greater test coverage than manual testing.
Test execution	Tests are run manually by QA testers.	Tests are run automatically (using automation tools and test scripts)
Types of tasks	Entirely manual tasks.	Most tasks can be automated, including real user simulations.
Scalability	Manual testing can only be scaled with more testers engaged and more hours allocated to a project so it does not scale well.	Automation enables a high level of scalability as you can simply just add more test executors with the testing tool.
Flexibility	Inherent benefits of manual testing are full control of the testing for manual testes and high level of flexibility in terms of how to execute single tests. As the workload increases, however, the flexibility decreases.	As automated testing is usually applied for more stable features, test cases are built one or two sprints after the implementation of those features. Gradual building of test cases means a high degree of flexibility.
Ideal approach	Manual testing proves useful when the test case only needs to run once or twice.	Automated testing is useful when frequently executing the same set of test cases.
Organization	Test teams are organized around products. This results in dedicated teams with a solid domain knowledge.	The roles within the test team differ with regard to technical proficiency and the level of domain knowledge.
Cost-effectiveness	Not cost effective for high volume testing (mainly regression).	Not cost effective for low volume testing.
Testing time	Manual testing is time-consuming and takes up human resources.	Automated testing is significantly faster than a manual approach.
Deadlines	Manual testing has a higher risk of missing out the pre-decided test deadline	Automated tests have zero risks of missing out a pre-decided test.
UI changes	Minor changes like change in id, class, etc. of a button do not impact the work of a manual tester.	Even trivial and minor changes in the UI of the AUT require automated test scripts need to be modified to work as expected.
Parallel tests execution	Manual tests can be executed in parallel, however, this requires much more investment into human resources to run them.	Automated testing can be executed on different operating platforms in parallel so that they reduce the test execution time.
Performance testing	Performance testing is not feasible manually.	Performance tests like load testing, stress testing, spike Testing, etc. have to be tested by an automation tool compulsorily.
Batch testing	Manual tests cannot be batched.	You can easily batch multiple test Scripts for nightly execution.
Test reports visibility	Manual tests are usually recorded in an Excel or Word, and test results are not readily available.	With automated testing, all stakeholders can login into the automation system and check the test execution results.
DevOps	Manual testing defeats the automated build principle of DevOps.	Automated testing helps in build verification testing. Such tests are an integral part of DevOps cycle.
Documentation	Manual test cases provide no training value (no testing documentation available immediately).	Automated testing tool provides documentation for test runs. Thus, it provides training value, especially for automated unit test cases. A new developer can look into a unit test cases and understand the code base quickly.

What is manual testing?

Manual testing is typically conducted on the basis of test scripts or test cases which are created by the testing team lead or senior testing team members. The test cases are created manually, without using the automated testing tools or frameworks. The standard manual testing life cycle consist of the following steps:

Analyzing requirements review:
testers need to read and understand the software project documentation. If available they should also study the Application Under Test (AUT)
Writing test cases:
this phase consists in drafting test cases that cover all the testing requirements mentioned in the documentation
Conducting test cases:
100% test cases is executed on the basis of AUT
Logging bugs:
errors and defects found during testing are reported.
Retesting defects:
once all the bugs have been fixed, the test runs are executed again for the failed test cases in order to verify if they pass.

The purpose of manual testing is to identify bugs, issues and any defects in the software application. It requires a lot of effort, however it is sometimes required in order to check automation feasibility.
The reported defects are fixed by the developers who then do the re-testing on the fixed defects. The key concept of manual testing it to ensure that once the application has been cleansed and it is bug-free, it is working in accordance with pre-defined rules.

What is automation testing?

Automated testing is a software testing technique that for executing a test case suite employs automated testing software tools. If we compare automated vs manual testing, the main and most obvious difference is that in manual testing, the tests are performed by a human sitting in front of the computer (and not automatically by software).
Automated testing demands considerable investment, both in terms of money and resources. However, using an automated testing tool, it is possible to record the test suite and re-play it as and when required. No human intervention is needed. This improves the ROI of test execution. Test automation software also allows for entering the test data, comparing the expected vs actual results and generating detailed test reports and audit documentation.

Automated testing is the best way to ensure high level of scalability, flexibility, effectiveness and test coverage as well as the fastest execution speed. It also reduced the risk of human error when running the test cases (which is high in manual testing due to human intervention).

Pros and cons of automated vs. manual testing

Each method of testing has its own pros and cons. Knowing them beforehand might help you prepare better for potential challenges and bottlenecks and decide when to deploy manual or automated testing.

Manual Testing

Advantages of manual testing:

It is less costly (you don’t need to spend the budget on test automation tools and framework)
You get fast and accurate visual feedback
For testing small items, you can do the testing on the fly instead of coding
You can use human judgement and intuition

Disadvantages of manual testing:

Very time consuming and tiring for the testers
Less reliable as prone to human error
Manual tests cannot be reused (recorded)
Certain tasks are very difficult to test manually so this requires additional time for software testing

Automated Testing

Advantages of automated testing:

It offers wider test coverage than manual testing
Process is speedy and efficient
Automation processes can be reused (as they get recorded) to execute the same kind of testing operation
Automated testing finds more bugs than a human tester is capable of
It increases productivity – testing results are provided faster and are more accurate
It supports testing across various applications.
As automated software uses software tools it is significantly less tiring than manual testing

Disadvantages of automated testing:

With no human element, it is hard to get insight into visual aspects of UI
Automated testing tool are costly and impact the costs of the testing projects
Every automation tool has its limitations (reduced scope of automation)
Automated test maintenances is costly (debugging the test scripts)