Users' Requirements are usually incomplete and inaccurate.
Sometimes, some important details have not been written into the requirements. Maybe users have forgotten them, but more often they think that those things are natural and take for granted. however, developers are not clear about these "natural events.
No matter how many requirements documents are written, it is necessary for us to repeatedly communicate with users to refine the requirements and clarify the details. Often, "Details determine success or failure ".
Use case is a good tool for communication with users. You can Use text to write various cases, or Use UML to draw a case. sending the Use case you understand to the user is a good way to communicate.
No matter what form is used, each use case has three things:
1. Have clear objectives
2. There are start points and end points
3. There are initiators (persons or external interfaces, external systems)
Supplement to requirements:
- Make sure that your system is what the customer really wants.
- Check that your system has done all the steps and paths described in usecase
- Help customers find out what they may have forgotten (or forget to tell you)
- There is no static demand, and demand is always changing (or growing)
- Use case can help you find incomplete or incorrect user requirements