Why is Manual testing necessary when developing a project?

                    “Automation is a part, but Manual is Heart of testing”

Manual software testing is the process where each individual part of software is verified by a tester, without using any script or tool and compared with the expected results, in order to find the defects (also called bugs) of the software.

Basically, using manual testing, the tester can see and use the software as a user would, which could be a very important factor for development, as the tester could also give improvements and ideas that would make a smooth user experience.

Although manual testing is a tiresome and unexciting process sometimes, it is more flexible than automated tests, when you have a very complex project, with many variables and where changes are made constantly.

For example, I’ve worked for a while on a very big project, where the client was quite difficult and changed his mind a lot. Although some automated tests were created for the project, after the changes were made, the tests could not be used anymore and needed improvements. These improvements would cost a lot since time is needed to be invested in the tests each time a change like this is made, so the manual testing is more imperative in this case.

Although some may think that automated tests are faster, keep in mind that there are a lot of tests that take hours to complete (some tests could take even 24h to complete) and if you need a quick result for a test, manual testing will give you the answer you need in no time.

Manual testing also is required when visual elements must be checked. For example it is difficult and quite expensive to create an automated test case to check if each color, font or image is rendered correctly or if the front end elements are correctly displayed for different browsers or devices. Essentially, manual testing is needed when performing compatibility tests since the costs to create automated tests might not justify the benefit.

While the automated tests are indeed needed in regression testing (when you need to check the same elements repeatedly), load testing and performance testing, the manual testing will be best eligible for exploratory testing, usability and ad-hoc testing, where the human tester can use his knowledge, experience, creativity and logical skills to find the defects of the software, to determine if the software is user-friendly, efficient and ready for the end users.

Finally, there are many opinions regarding the usability of automated or manual tests, but if you still think that manual tests are not essential, think about the following: how are you going to test your automated tests? :)