Correct order of steps for building a use case diagram.
- Set the context of the target system. Context always comes first. Without it, there is no frame of reference for the information you are evaluating.
- Identify the actors. Find the people, systems, or devices that communicate with the system. These users will become your source for finding and validating the required features of the system. This should be a first-draft effort only.
- Identify the use cases. Find the features that the system provides. What does the system help the actor(s) do? What does the system tell the actor? What does the actor help the system do? This should be a first-draft effort only.
- Define the associations between actors and use cases. Identify which actors need access to which features.
This should be a first-draft effort only.
- Evaluate the actors and use cases to find opportunities for refinement. Rename, merge, and split actors and use cases as needed. Update the related associations.
- Evaluate the use cases to find opportunities for delegation. Apply the
<<Uses>> association stereotype between the use cases.
- Evaluate the actors and use cases for special cases. Apply the
<<Extends>> association stereotype.