BoltedDown

I am currently learning OOAD and are having some trouble with sequence diagrams. Could someone please recommend a site that explains the procedures.

BTW, i'm using Rational Rose Prof. J Edition.

Thanks!

T.U.B.

I'm sorry, I do not know any sites by heart. However, I'm quite familiar with Rational Rose and OOAD. Ask away and we'll see how far we get.

Just a quick-start (you probably know all these things, but just in case...):

- a sequence diagram is based on the class diagram and the use case diagramma. Those two have the building blocks for the sequence diagram.
- 1) place the initial actor at the left of your diagram. This is the actor that will start up the functionality you are describing.
- 2) place the objects who are participating in the process from left to right in the sequence diagram in order of appereance.
- 3) from every object, draw a lifeline. (the dotted line down)
- 4) Activation is the rectangular on the life line. (Activation: the operation that the object makes)
- 5) Place the messages that the objects are sending and receiving horizontaly between the activation of the objects.

(sorry for my language, but i'm still a bit sleepy and never been good at translations of my mind)
Hope this makes things clearer. If not give a shout and i'll do my best.
I remeber my first OOAD lessons... Green! that was the color of my face...
but once you get the hang of it, it goes all well...

__________________
Amerika by Franz Kafka
“As Karl Rossman, a poor boy of sixteen who had been packed off to America by his parents because a servant girl had seduced him and got herself a child by him, stood on the liner slowly entering the harbour of New York, a sudden burst of sunshine seemed to illumine the Statue of Liberty, so that he saw it in a new light, although he had sighted it long before. The arm with the sword rose up as if newly stretched aloft, and round the figure blew the free winds of heaven.”

BoltedDown

The way that my professor taught it to us was... as you read through your use case description, pick out all the relevant nouns. Those will be our objects. And all of the relevant verbs will be our behaviors.

Does this sound right?

T.U.B.

that is correct. (for making a class diagram)
Out of your use case descriptions you make your class diagram.
The class diagram gives you the objects to work with in your sequence diagram, the logic of the use case diagram gives you the existancy of the object.
With other words: The sequence diagram gives you the existancy of the objects out of the perception of the actor(s) in time, by use of the flow of information between the objects (and/or actor(s)).

(I'm away untill friday, but if you like an example I'll be glad to make one when I'm back.)

__________________
Amerika by Franz Kafka
“As Karl Rossman, a poor boy of sixteen who had been packed off to America by his parents because a servant girl had seduced him and got herself a child by him, stood on the liner slowly entering the harbour of New York, a sudden burst of sunshine seemed to illumine the Statue of Liberty, so that he saw it in a new light, although he had sighted it long before. The arm with the sword rose up as if newly stretched aloft, and round the figure blew the free winds of heaven.”

BoltedDown

I have a second Iteration due next thursday. Would you mind if I ran my sequence diagrams by you?

skitz0

Get UML Distilled, its a short read and will give you everything you'd ever want/need to know about UML

BoltedDown

Thanks skitz0, i'll take a look at it!

T.U.B.

I don't mind to have a look at it...

But a few points to keep in mind:
- I'm not an analyst; I'm a programmer who knows OOAD.
- Analysis is not a science; It is subjective. It could be that you say A, your prof says B and I say C and all the 3 solutions are equaly correct.

I'm just digging myself in here, actually. I'm just saying: "Yeah, i'll have a look, but I rather give no better solution then a faulty 'better' solution".

If you are going to post your project, please do not only post the sequence diagram, but also the use case diagram, the relevant use case descriptions and the class diagram as it is now. And maybe a short description of what the project is about...
Also, are the use cases already corrected by your prof? (If yes, I'll keep my hands of then.)

It will be handy if you just post screenshots of the diagram, I have an older version of RR and RR is not good in version compatibility (sp?)...

__________________
Amerika by Franz Kafka
“As Karl Rossman, a poor boy of sixteen who had been packed off to America by his parents because a servant girl had seduced him and got herself a child by him, stood on the liner slowly entering the harbour of New York, a sudden burst of sunshine seemed to illumine the Statue of Liberty, so that he saw it in a new light, although he had sighted it long before. The arm with the sword rose up as if newly stretched aloft, and round the figure blew the free winds of heaven.”

BoltedDown

Thanks T.U.B.! If I have any issues, i'll shoot them your way. Of course, after our professor graded the first iterations. He explained everything we needed to know prior to turning them in. Gotta love it... Anyway, iteration 2 should be easier, as it is basically a revision of R1.