Functional testing

This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. Find sources: "Functional testing" – news · newspapers · books · scholar · JSTOR (December 2010) (Learn how and when to remove this message)

In software development, functional testing is a form of software system testing that verifies whether software matches its design.

Generally, functional testing is black-box meaning the internal program structure is ignored (unlike for white-box testing).^[1]

Functional testing can evaluate compliance to functional requirements.^[2]

Sometimes, functional testing is a quality assurance (QA) process.^[3]

Functional testing differs from acceptance testing. Functional testing verifies a program by checking it against design document(s) or specification(s), while acceptance testing validates a program by checking it against the published user or system requirements.^[4]

As a form of system testing, functional testing tests slices of functionality of the whole system. Despite similar naming, functional testing is not testing the code of a single function.

The concept of incorporating testing earlier in the delivery cycle is not restricted to functional testing.^[5]