An important component of the SDLC is software testing. It helps to guarantee that apps work as planned and fulfill quality requirements before they are distributed to end users. Testing may be done both manually and using automated techniques. Manual and automated testing have benefits and limitations.

Using the right testing strategy demands understanding the strengths and limitations of each approach. This guide provides a strategic overview of manual and automated testing to help teams optimize software quality.

Definitions of Manual and Automated Testing

Manual testing is a kind of software testing where a human tester carries out test cases without using automated technology. The primary objective of manual testing is to identify and localize any bugs, vulnerabilities, or imperfections in the software product. Testers perform each test step manually and then compare the acquired data with the expected outcomes.Manual testing requires substantial exertion and duration, however, it enables testers to use intuition, expertise, and discernment to assess software quality. It is effective for tasks of less scope and when automation is impossible.

Automated testing refers to using software tools to execute pre-scripted tests on the system under test. The scripts contain test cases that are executed automatically by testing tools. So, automated testing uses software tools to automate the execution of pre-defined test cases and scripts. It allows fast, consistent, and repeated testing cycles.

Pros and Cons of Manual Testing

Pros

• Speed: Manual testing can be performed quickly without the need to write automation scripts. Testers can start testing immediately after the software build is ready. This allows for rapid validation of new features and bug fixes.
• Cost: Manual testing has a lower startup cost compared to automated testing. There is no need to purchase automation tools or invest in script development and maintenance. The only major costs are the tester’s time and effort.
• Flexibility: Manual testers can respond on the fly to changes in the application under test. They can explore different usage scenarios and test flows based on their intuition and domain expertise. Automated scripts may need rework when the application changes.

Cons

• Repeated Efforts: Test cases need to be executed manually every time a new build is available. This can be tedious and error-prone for repetitive tests.
• Scalability: As the size of the application grows, the number of test cases increases. Executing all those test cases manually requires a lot of time and human resources.
• No Re-usability: The knowledge gained from manual testing cannot be re-used for regression testing. Testers must start from scratch for each iteration of the software development lifecycle.
• Human Errors: Manual testing is prone to mistakes as humans can miss defects due to distractions or lack of concentration. Boredom from repetitive tasks can also affect thoroughness.

Pros and Cons of Automated Testing

Pros

• Speed: Automatic tests can operate significantly quicker than manual tests. They allow you to run your test suite quickly and frequently, which is especially beneficial for regression testing. Tests can be run in parallel, allowing many tests to be executed at once.
• Cost: In the long run, the investment in automation pays off. While initial setup requires time and expertise, once tests are automated, they can be run over and over with minimal effort. This reduces the manual testing time and labor costs.
• Reliability: Automated tests perform the same steps precisely each time, eliminating human error. They are more reliable for finding defects and don’t get bored or fatigued like manual testers.

Cons

• Upfront Investment: There is a significant initial time and monetary investment to develop and integrate automated testing frameworks into the testing process. Also requires expertise.
• Maintenance: Automated tests need to be updated and maintained as the application changes over time. If the application UI changes significantly, many automated tests may need updating.
• Unsuitable for Exploratory Testing: Automated testing is not well-suited for exploratory, ad hoc testing. It works best for predefined, repeatable test cases.
• Flakiness: Automated tests can sometimes fail or pass unexpectedly. Flaky tests lead to false positives/negatives and require maintenance effort.
• Can’t Replace Manual Testing Completely: Automated testing has limitations in areas like usability, visual design, etc. It cannot replace manual testing completely.

When to Use Manual Testing

Manual testing is best suited for certain types of tests where human insight, intuition, and creativity come into play. Here are some of the key situations where manual testing shines:

New Feature Testing

When new features are developed, manual exploratory testing helps understand how the feature works, whether it flows well, and if there are any obvious bugs or issues. Rather than scripting tests upfront, a manual tester can explore the feature from an end user’s perspective, trying different usage scenarios and combinations. This provides rapid feedback during development.

Exploratory Testing

With manual testing, testers can apply their intuition and domain experience to test areas that may be missed by automated scripts. Exploratory testing is an ad hoc approach where testers freely explore the system, rather than following predefined test cases. Bugs that demand out-of-the-box, creative thinking to uncover are often caught during exploratory manual testing.

When to Use Automated Testing

Automated testing is particularly useful for:

Regression Testing

Regression testing checks that a code change does not break existing functionality. This involves repeatedly running tests for all features after any code changes.

Manual regression testing is extremely time-consuming and repetitive. Automated tests can be run quickly and frequently with minimal effort. Automated regression testing provides confidence that the application still functions correctly after changes.

Load Testing

Load testing evaluates application performance under heavy user loads. This simulates many concurrent users to identify bottlenecks.

Manual load testing is limited in how many virtual users can be generated. Automated tools can simulate thousands or millions of concurrent users applying load to the system. This reveals performance issues that would be extremely difficult to find manually.

Particularly crucial for web applications and APIs that must manage traffic surges is automated load testing. It guarantees the scalability of the system well in advance of its launch.

Conclusion

When it comes to manual and automated testing, each of these methods has its advantages and disadvantages. The best approach will depend on the business demands and requirements. However, utilizing a combination of both, leveraging the strengths of each to maximize test coverage and software quality.

The optimal strategy is to automate the testing of important functionality that requires regular regression testing. This allows more time for manual exploratory testing of new features and difficult test cases. Test automation should augment, not replace, manual testing efforts. Teams may maximize the efficiency and coverage of testing by combining the two methods.