In software and systems engineering, a use case is a list of steps, typically defining interactions between a role (known in Unified Modeling Language (UML) as an `actor`) and a system, to achieve a goal. The actor can be a human, an external system, or time. In systems engineering, use cases are used at a higher level than within software engin..... Found on http://en.wikipedia.org/wiki/Use_case
(ITIL Service Design) A technique used to define required functionality and objectives, and to design tests. Use cases define realistic scenarios that describe interactions between users and an IT service or other system. Found on https://www.encyclo.co.uk/local/22879