Acceptance Testing

This was originally called "functional testing" because each acceptance test tries to test the functionality of the application to ensure it does what it is supposed to.

Acceptance tests are different from unit tests in that unit tests are usually written, conducted, and assessed by the developers themselves, while the acceptance test is planned and conducted by members of the customer organization's end-user teams.

If the unit test answers "does it behave according to functional requirements," then the acceptance test attempts to answer, "can we use it to fulfill our business needs, given that we believe those needs are adequately represented in the requirements for this system?" Acceptance testing generally involves running a suite of tests on the completed system once it is ready, and the individual test, known as a case, exercises a particular operating condition of the environment or feature of the system and will result in a pass or fail outcome. While it's ideal to have a clean yes/no acceptance decision, most custom-built systems are sufficiently complex, and business needs so pressing, that accepting a system with an identified set of known discrepancies and a corresponding resolution and workoff plan is commonplace.