Functional Testing or Functional Testing

Functional testing examines predetermined behavior and is based on an analysis of the specifications of the functionality of a component or system as a whole.

Functional tests are based on the functions performed by the system, and can be conducted at all levels of testing ( component, integration, system, acceptance ). As a rule, these functions are described in requirements, functional specifications or in the form of use cases .

Testing functionality can be carried out in two aspects:

• requirements
• business processes

Testing in the "requirements" perspective uses the specification of functional requirements for the system as the basis for the design of test cases ( Test Cases ). In this case, it is necessary to make a list of what will be tested and what is not, prioritize requirements based on risks (if this is not done in the requirements document), and based on this, prioritize test scenarios (test cases). This will allow to focus and not to miss the most important functionality when testing.

Testing in the perspective of "business processes" uses knowledge of these same business processes that describe the scenarios of daily use of the system. In this perspective, test scripts are usually based on the use cases of the system.

The advantages of functional testing :

• imitates the actual use of the system;

Disadvantages of functional testing :

• the possibility of omission of logical errors in software;
• probability of over testing.

Automation of functional testing is quite common.