UML Class Reviewing (3/4 7th Sep 2010)

How can I draw the use case diagram?

Use case diagram needs 3 notations.

Ellipse symbolizes the use case.

We write the use case we need in it.

Rectangle symbolizes the boundary.

One system or conponent shows in it.

Stick man symbolizes the actor.

Actor can be not only the user, but the engineer and so on..

It is possible if the actor is not human.

<<include>> is used when one use case can be said it is one part of the other use case.

<<extend>> is used when one use case can be said a developed use case of the other use case.

How can I draw the activity diagram?

First dot means start.
We write the action the actor do in the system into the rectangle.
If the actor do the several actions in the same time, we can draw like Action2 and Action3.
We can use the branch.
Acording to the decision, we can choose the next action.
The last dot means end.


How can I draw the state machine diagram?

State machine diagram  shows the transition of object's state.
There are invalid activities in some states.
For example, the car cannot start when the engine doesn't work.
We can see like that condition from this diagram.
The state is write in the ellipse.
We draw the next state which will be changed by the event.
We can use the branch, but the importance is to be easy to see.
If the branch makes diagram complicated, we should not use the decision.

How can I draw the sequence diagram?

First we should enumerate the object or component we need in the process.
Write the action or interaction between the objects at each process.
After Action1, the user get the response.
The action which recieve the reaction like this is called syncronus.
The action which doesn't recieve the reaction like Action3 is called Asyncronus.