<P> In software and systems engineering , a use case is a list of actions or event steps typically defining the interactions between a role ( known in the Unified Modeling Language as an actor ) and a system to achieve a goal . The actor can be a human or other external system . In systems engineering use cases are used at a higher level than within software engineering often representing missions or stakeholder goals . The detailed requirements may then be captured in the Systems Modeling Language ( SysML ) or as contractual statements . </P>
what is use case model in software engineering
a list of actions or event steps typically defining the interactions between a role ( known in the Unified Modeling Language as an actor ) and a system to achieve a goal