What is Functional and Non Functional testing
Using Functional Testing

What does Functional Testing Means:

                Functional testing and Non-Functional Testing is all about smart testing of the software for the specific coding errors and ensuring the work is exactly as needed as it is supposed to be and later testing too. The world has taken over by technology and in the era we are approaching, we can expect further advancement. Moreover these machines ranging from small remote control car to the high tech robot or any heavy space shuttle going to the outer space. All the technology we use today is done by coding with a certain programming and checking the execution. But will these program codes will function as the developer presumes.This answer is provided by Functional Testing.

Software testing

It is the process of evaluating the functionality of software to detect any software bugs. This testing checks whether the required software is executing the specified requirement or not. It identifies any defect in software to result in a quality product. Functional testing is a part of Software testing which specifically verifies each function of the software application operates in conformation with requirements. It basically focuses on the black box testing and not the source code testing. We check functionality of a system by giving an appropriate input and verifying the output. Then comparing the actual result with the expected result.

What does Non Functional Testing means:

On the other hand there is something called Non-Functional testing and weighs equally important as Functional testing is. It affects the client’s satisfaction. It is a type of Software testing which verifies the non-functional aspects like performance, usability, reliability, etc within a software application. Especially designed to test the agility and response of the system. As per Non-Functional parameters speed and quickness are not part of functional testing. In this type of checking, we observe the behavior of software when large number of people simultaneously log into it.

 Difference between Functional and Non-Functional Testing:

Eventually a question arises in our mind, what is the difference among them and why is both are separate and not same? While Functional testing is for verifying the software actions, latter is to verify the performance of software. Functional testing is to work on the user requirement and defining how the software works. Whereas, Non Functional is based user expectation and focuses on how good the software has executed the function. Being that, functional takes place before the Non Functional testing.

Improving Functional testing:

Although both testings are important, we give more preference to functional testing. According to us, Some basic tips for preparing a high class testing is mostly by mixing the manual and automated testing. Preferably, best strategy to test the program is using black box testing. Through which the checker doesn’t require reviewing the internal source code and validate the functionality by testing as follows:

  1. Testing through Installation.
  2. Partitioning how it works on group logins and overlaps.
  3. Value Analysis of the boundaries for numerical limits.
  4. Checking where the issues in functions come through assuming values and testing on these random values.
  5. Verifying the internal and external API.
  6. Testing at the unit level and deciding how the whole bundle will work together.
  7.  Outcomes that results on bringing small changes in the software input.

These functional tests carry specific outputs expected for any input data. Expecting an acceptance on entering a valid data is compelling. Hence, it is very affirmative to test all functional tests which can be analyzed as clear pass or fail criterion.

Improving Non-Functional Testing:

Similarly for Non-Functional Testing strategy we use few tricks executing software with a high success rate. Ultimately it requires high creativity and technical expertise of the developer, as it checks the overall execution of the software.

  1. Testing how the software works in Loaded Condition on simulated environment when loads of users are online on same time.
  2. Listing of how the software behaves on low resources criterion.
  3. Testing the performance of the software with a large volume of data sourcing.  It may not necessarily require high number of users.
  4. Testing the security of the software to check the level of prone to attackers and accessibility.
  5. Ease of Recovery of details and data on disaster erosion.
  6. Checking for the User experience of the software and the ease of usage.


Even at times of malfunctioning as a result of Non functional testing, it is necessary the developer or the owner uses the technique to ensure clarity and quantify the resultant output software for happy customer. To summarize, listening to the customers’ feedback is necessary for stay updated about the Non-Functional requirements; because these feedback can set up base of where and how to execute the software whereas with the Functional Testing procedure, we don’t need the base is which is already set of how to do it.

1 Comment

pooja · August 6, 2019 at 7:05 am

your blog are really helpful for all testers and beginners.this all provided knowledge are unique than other functional-testing blog.
lovely explain.
keep updating,Thanks

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