unit: See component.
unit test framework: A tool that provides an environment for unit or component testing in which a component can be tested in isolation or with suitable stubs and drivers. It also provides other support for the developer, such as debugging capabilities.
unit testing: See component testing.
unreachable code: Code that cannot be reached and therefore is impossible to execute.
usability: The capability of the software to be understood, learned, used and attractive to the user when used under specified conditions.
usability testing: Testing to determine the extent to which the software product is understood, easy to learn, easy to operate and attractive to the users under specified conditions.
use case: A sequence of transactions in a dialogue between an actor and a component or system with a tangible result, where an actor can be a user or anything that can exchange information with the system.
use case testing: A black box test design technique in which test cases are designed to execute scenarios of use cases.
user acceptance testing: See acceptance testing.
user-based quality: A view of quality, wherein quality is the capacity to satisfy needs, wants and desires of the user(s). A product or service that does not fulfill user needs is unlikely to find any users. This is a context dependent, contingent approach to quality since different business characteristics require different qualities of a product.
user scenario testing: See use case testing.
user test: A test whereby real-life users are involved to evaluate the usability of a component or system.