Functional testing means testing the application against business requirements. Functional testing is executed using the functional specifications given by the client or by the design specifications according to use cases given by the design team. Role of functional testing is to validating the behavior of an application.
Functional testing falls in to two categories:
Functional testing is more important because it always verifies that your system is fixed for release. The functional tests define your working system in a useful manner. In functional testing tester has to validate the application to see that all specified requirements of the client whatever we have said in SRS or BRS have been incorporated or not.
Functional testing is always concentrating on customer requirements and whereas the Non-Functional testing is always concentrating on customer expectations.
Functional testing is always concentrating on customer requirements and whereas the Non-Functional testing is always concentrating on customer expectations.
Functional and Non Functional Test Cases
Functional test cases target business goals and non functional test cases target performance, resource utilization, usability, compatibility etc. Functional testing is a part of system testing.
Example of functional testing is explained below
Considering example if you are functionally testing a word processing application, a partial list of checks you would perform minimally includes creating, saving, editing, spell checking and printing documents.
Types of Functional Testing
Functional testing falls in to two categories:
1. Positive functional testing: - This testing carry exercising the application's functions with valid input and also verifying that the outputs are correct.
Example:-
Again continuing with the word processing example, a positive test for the printing function might be to print a document containing both text as well as graphics to a printer that is online, filled with paper and for which the correct drivers are installed.
2. Negative functional testing: - This testing involves exercising application functionality using a combination of invalid inputs, some unexpected operating conditions and by some other "out-of-bounds" scenarios.
Example:-
Again continuing with the word processing example, a negative test for the printing function might be to disconnect the printer from the computers while a document is printing.
What probably should happen in these scenarios are a plain-English error message displayed, informing the user what happened and instructing him/her on how to fix the problem.
Conclusion:
At last we conclude that in functional testing functionality of the module is tested and structure is not considered. It is performed, based on user's perspective. These tests ensure that the system does what users are expecting it to do.
This type of testing means testing the functionality example include input the proper data and checking the output as per the requirement documents.
Before us proceeding towards the Difference between Functional and Non Functional Testing it is very important for us to first take a brief look at Functional and Non Functional Testing.
Functional and Non Functional Testing is what?
Functional testing is performed using the functional specifications provided by the client or you can say by using the design specifications like use cases provided by the design team.
In this, tester has to test the application to see that all requirements of the client which he has said in SRS and BRS have been incorporated or not.
Non Functional Testingis that which is always concerned with the client expectations like performance, load and stress issues and so on.
Distinction between Functional and Non Functional Testing
Functional Testing
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Non- Functional Testing
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1. In functional Testing tester tests how well the system performs.
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1. In Non-Functional Testing tester tests how well the system responds.
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2. Functional Testing is based on client requirements.
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2. Non- Functional Testing is based on client expectations.
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3. Functional Testing means Testing the application against business requirements.
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3. Non- Functional Testing means Testing the application against clients and performance requirements.
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4. It is a part of System Testing.
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4. It is also a part of System Testing
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5. Functional Testing Validating the behavior of application.
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5. Non- Functional Testing Validating the performance of application.
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6. This Testing covers Unit Testing, Integration Testing, Smoke Testing, Sanity Testing, Regression Testing and so on.
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6. This Testing covers Load/Performance Testing, Stress/Volume Testing, Security Testing, Installation Testing and so on.
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7. It is always concentrating on customer requirements.
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7. It is always concentrating on customer expectations.
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8. Functional Testing means how is your system is doing.
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8. Non- Functional Testing means how well your system is doing example usability, performance and stress testing.
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