What is the essence of usecase?
I think the executor how to meet the representation of the interests of the people.
Common use cases include the following partial:
Use case name
Executor
Involve
All-in-law
Basic path
Expansion path
constraint
How to find the use of the use case and the expression of the use case is the right interest.
Only by finding the true interests of the people can guarantee the successful implementation of the project
The most useful way is to assume the failure method, remove the case from the system, and how to find a real use case quickly and accurately.