Pros and Cons of Automated and Manual Testing


Software testing is a process by which we search for software product bugs and improve overall application performance.

We test to detect negative issues that may affect the experience of using the application and we can tell apart between automated and manual testing.

In one of our previous articles, we talked about why automated testing makes sense for your startup development.

We now want to discuss the advantages of these tools as compared to less advanced ones such as manual tools.

What is automated and manual testing?

Manually testing is done by hand. Quality Assurance specialists ensure that applications work properly by following conditions written in test cases. Manual testing is still crucial, as certain functionality simply cannot be tested automatically. For example, wearables are mobile devices that can require field testing in a physical environment. Mobile applications often undergo ‘monkey tests’ where bottlenecks are detected under stressful conditions only able to happen in the real world. For instance, what if an automated device were to be left in someone's pocket and they accidentally pressed the screen? What would happen - they might just press the button again.

Automated testing is the practice of executing tests through a system instead of manually. Automated tools can execute repetitive tasks and regression tests to check if an application performs correctly after newly implemented changes.

Here, we are going to discuss automated versus manual testing in detail.

Automated Testing

Automated testing is an important part of Test-Driven Development (TDD), which is characterized by the writing of test cases for each unit (unit tests) before the actual code is written. After these unit tests are written, they can be run to see if there are any errors or flaws with them, and then if there aren't any issues, these products will then be debugged for errors or certain improvements that may be needed. Our company heavily utilizes this approach at Distinct Cloud to build numerous products throughout the industry using many different programming languages.

As a rule, our QA team checks if the following types of testing have been performed:

  • Unit Testing - Testing of discrete parts (units) of a software product.
  • Functional Testing - Software QA testing is performed to detect the actual performance of an application’s functional requirements. Functional testing usually considers accuracy, interoperability, compliance, security, compatibility and suitability.
  • Regression testing (a type of functional testing) - Checks if an application performs correctly after being modified or integrated with other software.
  • Automated GUI testing – Testing the look and feel attributes to see if the app meets whatever standards we need.

These are just some of the test types we automate to save time and money and to eliminate human error when it comes to code reliability. Now let's see what sorts of problems we can solve when we take advantage of automated testing!

Why do you need automated testing?

  1. To mitigate time-consuming tasks. After changes and modifications are made to an application, you need to check if it functions properly. By executing automated tests after functional modifications, you can ensure that all aspects of your program’s functionality are up to par.
  2. To repeatedly execute the same set of tasks. If you're constantly adding the same features or carrying out the same operations in a project, then the handy nature of automated tests makes them great for recurring processes.
  3. -To eliminate human error. Automated tests are powered by tools and scripts, so the chance of missing a bug or a defect decreases. This makes for testing process more reliable and time-efficient.
  4. For advanced GUI testing." Automated GUI tests detect and record differences in behaviour between platforms—for example, across different web browsers or operating systems. Also, automated GUI testing effectively finds regression errors."
  5. To test load and performance. There’s essentially no manual alternative for testing load and performance. Automated tests simulate thousands of simultaneous users.

Manual Testing

It’s important to remember though that automated testing isn’t always the solution to evaluating a piece of software. For example, it’s not very likely you can automate certain types of manual tests as they require a high level of skill and expertise as well as experience to carry them out correctly. Now, let’s take a look at some (but not all) of the scenarios which might benefit from having both automated and manual testing in your development methodology:

  • Ad hoc testing – Testing which is executed without preparation and written test cases. During ad hoc testing, a QA specialist randomly tests the functionality of the system; his main aim is to be creative and “break” the system to discover flaws.
  • Exploratory Testing - this testing technique is sometimes confused with Ad Hoc Testing but they are different; in Exploratory Testing, a QA specialist designs test cases based on his personal experience whilst looking for non-regressions in the previous version of the product. By creating automated tests beforehand he can make sure the process is streamlined and that all aspects of the application are tested equally. This will allow him to maintain focus on what issues need to be addressed in quick succession.
  • User interface testing – a QA specialist examines interface elements to ensure that the properties and states of these elements are what they should be. Also, a QA team ensures that design elements in their interfaces match up with elements in the final layout.

Although it's assumed that the majority of tests will be automated, manual testing provides just as much value. It can provide an effective quality check of any bugs or improper functions. The trick with manual tests is not to trust the results too blindly without ever double-checking them by seeing if they proved true or not.

The cases where manual testing is best

  • UI Acceptance – Visual-based testing is key when it comes to UI acceptance. Manual tests are ideal for this because computers can't detect colours, links, size of signatures, gestures, and highlighting the same way humans can. This means that if you've got a bug in your application that makes a certain link or button so tiny that no person will ever be able to locate it with their eyesight; manual testers will immediately be caught this flaw but machines won't.
  • Initial development stage — Manual testing helps testers to detect bottlenecks during the initial development stage which results in less time and resources being spent on fixing bugs. In some approaches to software development, automated testing is a part of the process at any stage, but in others, it's not recommended to invest money and human resources in automated testing during an unstable phase of a product's development. However, for the most part, test automation is a highly useful tool that increases productivity within a project.
  • Short-term projects - While tests are designed to help save time and resources, it takes time and resources to design our automated tests. It's sometimes wise to rely on manual testing for projects that are small or have an extremely tight deadline. Let's talk about some other examples!
  • Non-automatable cases – Some tests cannot be automated; this especially concerns hardware-related tests. Writing scripts for automated checks of sensors, touchpads, and screens is almost impossible and rarely viable. Also, some data can be tested only manually. For example, you can test if a printer prints, but it’s best to check the quality and content of printed images by hand.


There’s no silver bullet when it comes to testing during the development process. While you can use automated and manual testing methods, sometimes our automated tests aren’t able to cover certain things. When this happens, you need to rely on your manual tests to fill in for any gaps that may exist or if you don’t have the tools necessary. There are also times where you need to combine different kinds of tests - like both automatically programmed and manually programmed – which means there is no single approach for doing these things. But one thing we can all agree on is that no matter how great automated tests are, they cannot fully replace a product manager's intuition about a customer experience.

At Distinct Cloud, we apply automatic testing as part of our Agile development approach. This empowers us to release higher quality software, save time and costs for recruiting and training new developers, and reduce waste by reducing time spent on maintenance provided that tests are maintained alongside the associated codebase. If you'd like to know more about how we use automated testing, microservices, continuous testing or just want advice on how to improve your own team's process then feel free to contact us.