??????????????????????????stakeholders???????????Use Case?????????????д??Ч??????????????壬???????????????
?????????????е???????????????
????1.Figure1.1 The "Hub-and-spoke" model of requirements?????UseCase??????????????
????2.Figure2.2 Striped trousers:Scenarios succeed or fail??????Scenarios?????????????????
????3.Figure5.1 Use case levels. The use case set reveals a hierarchy of goals --- the ever-unfolding story????????????????Summary Goals??User Goals??Subfunctions ?????????????????
????3.Figure5.2 Ask ‘‘Why‘‘ to shift levels?? ????????????Why??????How??
?????????????UseCase ?????
????Primary Actor
????Scope
????Level
????Preconditons
????Trigger
????Main Success Scenario
????Extensions
????Variations
????1?????????????????precondition???????????????????????????????????????????????????????????????????????????н????????á?
???????????????????????????????????????????????
??????????θ?????????????????п??·??????裬?????????κ???????????????????????????????????????????????????????????“???????”???????????????“???”???????????“???????????”?????“?????????”??????“???”???????????
????2?????д???????????????????????????????????????????????????д???????????
???????磬???????????????????????“???”????“????????”???????????
????3??С???????????????????????????????????????????????????????????????????????????????￡??????????????????????????????????С????????/???????????
????4??????????success guarantee?????????????????????????????????Щ??????????????????????????????????ó??????????????п??·????ó????????????????С?????????????С?????????????????Щ??????????棻????????????????????????????????????
????5??????????????????????????????????????????/??????????????????????÷??????????????????“?????????????????????????????е????????”?????????????????????д???????????
????6???????????trigger??????????????????????